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1

Organic Experiments for Introductory Chemistry.  

ERIC Educational Resources Information Center

Describes test-tube organic chemistry procedures (using comparatively safe reagents) for the beginning student. These procedures are used to: examine differences between saturated and unsaturated hydrocarbons; compare structural isomers; and compare organic and inorganic acids and bases. (DH)

Rayner-Canham, Geoff

1985-01-01

2

Cocrystal Controlled Solid-State Synthesis: A Green Chemistry Experiment for Undergraduate Organic Chemistry  

ERIC Educational Resources Information Center

Green chemistry has become an important area of concern for all chemists from practitioners in the pharmaceutical industry to professors and the students they teach and is now being incorporated into lectures of general and organic chemistry courses. However, there are relatively few green chemistry experiments that are easily incorporated into…

Cheney, Miranda L.; Zaworotko, Michael J.; Beaton, Steve; Singer, Robert D.

2008-01-01

3

Biodiesel Synthesis and Evaluation: An Organic Chemistry Experiment  

ERIC Educational Resources Information Center

A new lab esterification reaction based on biodiesel preparation and viscosity, which provides a model experience of industrial process to understand oxidation of vicinal alcohols by periodic acid, is presented. This new desertification experiment and periodate analysis of glycerol for the introductory organic chemistry laboratory provides an…

Bucholtz, Ehren C.

2007-01-01

4

Synthesis of Bisphenol Z: An Organic Chemistry Experiment  

ERIC Educational Resources Information Center

A student achievable synthesis of bisphenol Z, 4,4'-(cyclohexane-1,1-diyl)diphenol, from the acid-catalyzed reaction of phenol with cyclohexanone is presented. The experiment exemplifies all the usual pedagogy for the standard topic of electrophilic aromatic substitution present in the undergraduate organic chemistry curriculum, while providing…

Gregor, Richard W.

2012-01-01

5

Biodiesel from Seeds: An Experiment for Organic Chemistry  

ERIC Educational Resources Information Center

Plants can store the chemical energy required by their developing offspring in the form of triglycerides. These lipids can be isolated from seeds and then converted into biodiesel through a transesterification reaction. This second-year undergraduate organic chemistry laboratory experiment exemplifies the conversion of an agricultural energy…

Goldstein, Steven W.

2014-01-01

6

Radical Recombination Kinetics: An Experiment in Physical Organic Chemistry.  

ERIC Educational Resources Information Center

Describes a student kinetic experiment involving second order kinetics as well as displaying photochromism using a wide variety of techniques from both physical and organic chemistry. Describes measurement of (1) the rate of the recombination reaction; (2) the extinction coefficient; and (3) the ESR spectrometer signal. (Author/JN)

Pickering, Miles

1980-01-01

7

The Photochemical Isomerization of Maleic to Fumaric Acid: An Undergraduate Organic Chemistry Experiment.  

ERIC Educational Resources Information Center

Describes an undergraduate organic chemistry experiment on the photochemical isomerization of maleic to fumaric acid. Background information, chemical reactions involved, and experimental procedures are included. (JN)

Castro, Albert J.; And Others

1983-01-01

8

ORGANIC CHEMISTRY UCLA Organic Chemistry Faculty  

E-print Network

ORGANIC CHEMISTRY UCLA Organic Chemistry Faculty perform research in molecular machines, exotic CHEMISTRY FACULTY RESEARCH INTERESTS Anne M. Andrews, Professor-in-Residence: Understanding how areas of interest include cross- coupling reactions, green chemistry, heterocycle synthesis, and natural

Levine, Alex J.

9

An Enzyme Kinetics Experiment for the Undergraduate Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

An experiment using [superscript 1]H NMR spectroscopy to observe the kinetics of the acylase 1-catalyzed hydrolysis of "N"-acetyl-DL-methionine has been developed for the organic laboratory. The L-enantiomer of the reactant is hydrolyzed completely in less than 2 h, and [superscript 1]H NMR spectroscopic data from a single sample can be worked up…

Olsen, Robert J.; Olsen, Julie A.; Giles, Greta A.

2010-01-01

10

Chemistry Experiments  

NASA Technical Reports Server (NTRS)

The purpose of the chemistry component of the model comparison is to assess to what extent differences in the formulation of chemical processes explain the variance between model results. Observed concentrations of chemical compounds are used to estimate to what degree the various models represent realistic situations. For readability, the materials for the chemistry experiment are reported in three separate sections. This section discussed the data used to evaluate the models in their simulation of the source gases and the Nitrogen compounds (NO(y)) and Chlorine compounds (Cl(y)) species.

Brasseur, Guy; Remsberg, Ellis; Purcell, Patrick; Bhatt, Praful; Sage, Karen H.; Brown, Donald E.; Scott, Courtney J.; Ko, Malcolm K. W.; Tie, Xue-Xi; Huang, Theresa

1999-01-01

11

A Cost-Effective Two-Part Experiment for Teaching Introductory Organic Chemistry Techniques  

ERIC Educational Resources Information Center

This two-part laboratory experiment is designed to be a cost-effective method for teaching basic organic laboratory techniques (recrystallization, thin-layer chromatography, column chromatography, vacuum filtration, and melting point determination) to large classes of introductory organic chemistry students. Students are exposed to different…

Sadek, Christopher M.; Brown, Brenna A.; Wan, Hayley

2011-01-01

12

Examination of a Reaction Mechanism by Polarimetry: An Experiment for the Undergraduate Organic Chemistry Laboratory  

NASA Astrophysics Data System (ADS)

An undergraduate Organic chemistry laboratory experiment involving the use of polarimetry to determine a reaction mechanism is described. The experiment has been shown to be successful with chiral mandelic acid and POCl3 and with chiral lactic acid and HBr. The substitution mechanisms of these reactions proceed with 1% and 38% SN2 character respectively.

Mosher, Michael D.; Kelly, Chad O.; Mosher, Melvyn W.

1996-06-01

13

Analysis of Analgesic Mixtures: An Organic Chemistry Experiment.  

ERIC Educational Resources Information Center

Describes an experiment to analyze commercial analgesic preparations (pain relievers) by silica gel thin layer chromatography, followed by preparative (thick) layer chromatographic separation and spectroscopic analysis. Key difference from similar experiments is that students are responsible for devising suitable solvent systems for the thin layer…

Martin, Ned H.

1981-01-01

14

The Synthesis of a Cockroach Pheromone: An Experiment for the Second-Year Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

This experiment describes the synthesis of gentisyl quinone isovalerate, or blattellaquinone, a sex pheromone of the German cockroach that was isolated and identified in 2005. The synthesis is appropriate for the second semester of a second-year organic chemistry laboratory course. It can be completed in two, three-hour laboratory periods and uses…

Feist, Patty L.

2008-01-01

15

Solvent-Free Wittig Reaction: A Green Organic Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

Some Wittig reactions can be carried out by grinding the reactants in a mortar with a pestle for about 20 minutes, as per investigation. A laboratory experiment involving a solvent-free Wittig reaction that can be completed in a three-hour sophomore organic chemistry laboratory class period, are developed.

Leung, Sam H.; Angel, Stephen A.

2004-01-01

16

Using appropriate strategies to improve teaching and learning in organic chemistry and organic chemical experiment courses  

Microsoft Academic Search

In China, higher education needs to be reformed profoundly. This kind of reform must focus on making learning more efficient and improving educational practice. This is a challenge for us. Like other courses, the practice of teaching organic chemistry requires change in order to improve teaching and learning. This may require a rethink of our approach to education. In this

Yingjie Lin; Zaiqun Liu

2003-01-01

17

148 Chemistry/Chinese Chemistry 347 (3)--Advanced Organic Chemistry  

E-print Network

148 Chemistry/Chinese Chemistry 347 (3)--Advanced Organic Chemistry Prerequisite: Chemistry 242,syntheticmethodology,mod- ernsyntheticreactions,protectinggroups,naturalprod- uctssynthesis,andcombinatorialchemistry.France. Spring Chemistry 350 (3)--Advanced Inorganic Chemistry Prerequisites: Chemistry 250, 252, and 262. Anintro

Dresden, Gregory

18

The Teaching of Organic Chemistry in Schools--Can We Learn from the Kenyan Experience?  

ERIC Educational Resources Information Center

Describes a study of perceived difficulty of chemistry courses among secondary school and college students in Kenya. Concludes that organic chemistry may not be as difficult as many people believe. (CW)

Brook, David W.

1988-01-01

19

Chemistry 321 Organic Chemistry  

E-print Network

computer (HyperChem) homework sets, an NMR Homework set (2 problems), OWL homework, quizzes (clicker format will be given only five chances to solve each OWL homework problem. If you miss a problem, it is important of organic molecules, major reactions (approximately 50) and their mechanisms, synthesis, structure

Wagner, Diane

20

Teaching Catalytic Antibodies to Undergraduate Students: An Organic Chemistry Lab Experiment  

NASA Astrophysics Data System (ADS)

Only 13 years ago, few believed that antibodies could be catalytic or that any protein could be made to order to perform a catalytic task. The field has quickly matured from initial proof of concept and demonstration of fundamental enzyme-like characteristics to one in which antibodies have catalyzed an extremely broad range of organic transformations. Now that the first catalytic antibody is commercially available, it is possible to bring these novel biocatalysts into the classroom so every student can gain hands-on experience and carry out experiments on the cutting edge of scientific discovery. This lab project deals with antibody-catalyzed aldol condensations. It includes the (i) synthesis of substrate and product; (ii) HPLC characterization of the antibody-catalyzed reaction; (iii) titration of the antibody active-site; and (iv) analysis of the kinetics of the antibody-catalyzed reaction. The lab project provides training not only in biocatalysis but in a number of related aspects of chemical and biochemical research, including organic synthesis, mechanistic organic chemistry, and chemical kinetics. Students will learn the use of various experimental techniques, such as UV-vis spectroscopy and HPLC, to monitor chemical reactions and determine kinetic parameters. They will be exposed to concepts and terminology of bioorganic chemistry, such as protein structure and function, inhibition and active-site titration, and basic principles of biocatalysis.

Shulman, Avidor; Keinan, Ehud; Shabat, Doron; Barbas, Carlos F., III

1999-07-01

21

Insights Into Atmospheric Aqueous Organic Chemistry Through Controlled Experiments with Cloud Water Surrogates  

NASA Astrophysics Data System (ADS)

There is considerable laboratory and field-based evidence that chemical processing in clouds and wet aerosols alters organic composition and contributes to the formation of secondary organic aerosol (SOA). Single-compound laboratory experiments have played an important role in developing aqueous-phase chemical mechanisms that aid prediction of SOA formation through multiphase chemistry. In this work we conduct similar experiments with cloud/fog water surrogates, to 1) evaluate to what extent the previously studied chemistry is observed in these more realistic atmospheric waters, and 2) to identify additional atmospherically-relevant precursors and products that require further study. We used filtered Camden and Pinelands, NJ rainwater as a surrogate for cloud water. OH radical (~10-12 M) was formed by photolysis of hydrogen peroxide and samples were analyzed in real-time by electrospray ionization mass spectroscopy (ESI-MS). Discrete samples were also analyzed by ion chromatography (IC) and ESI-MS after IC separation. All experiments were performed in duplicate. Standards of glyoxal, methylglyoxal and glycolaldehyde and their major aqueous oxidation products were also analyzed, and control experiments performed. Decreases in the ion abundance of many positive mode compounds and increases in the ion abundance of many negative mode compounds (e.g., organic acids) suggest that precursors are predominantly aldehydes, organic peroxides and/or alcohols. Real-time ESI mass spectra were consistent with the expected loss of methylglyoxal and subsequent formation of pyruvate, glyoxylate, and oxalate. New insights regarding other potential precursors and products will be provided.

Turpin, B. J.; Ramos, A.; Kirkland, J. R.; Lim, Y. B.; Seitzinger, S.

2011-12-01

22

The Discovery-Oriented Approach to Organic Chemistry. 7. Rearrangement of "trans"-Stilbene Oxide with Bismuth Trifluoromethanesulfonate and Other Metal Triflates: A Microscale Green Organic Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

Although green chemistry principles are increasingly stressed in the undergraduate curriculum, there are only a few lab experiments wherein the toxicity of reagents is taken into consideration in the design of the experiment. We report a microscale green organic chemistry laboratory experiment that illustrates the utility of metal triflates,…

Christensen, James E.; Huddle, Matthew G.; Rogers, Jamie L.; Yung, Herbie; Mohan, Ram S.

2008-01-01

23

Organic Chemistry Resources Worldwide  

NSDL National Science Digital Library

Organic Chemistry Worldwide is an excellent organic chemistry metasite that is not to be missed. Geared toward synthetic organic chemists involved in academic or industrial research, Organic Chemistry Resources Worldwide has a mission to collect and independently annotate "all useful organic chemistry sites and to present them in an intuitive way." This extensive metasite is divided into sections on literature, laboratory resources, spectroscopy and spectrometry, nomenclature and teaching, and conferences and organizations. The Literature section contains links to over 75 journals (some restricted access), 14 free databases (and many more commercial), dissertation collections, reviews, guides, patents, and current awareness sources. Examples of resources for laboratory work include links to chemical product databases, laboratory safety bulletins (.pdf), products and services, etc. Highlights of the site are an in-depth section on mass spectrometry, with links to publications and databases, and a plethora of links to organic chemistry labs worldwide, from Armenia to Uruguay.

Van Aken, Koen

1996-01-01

24

Chemistry 675 (CHE 675) Advanced Organic Chemistry  

E-print Network

Chemistry 675 (CHE 675) Advanced Organic Chemistry Fall Semester 2011 Professor James Hougland675 is a graduate-level organic chemistry course that can be continued in the Spring semester as CHE685. These two courses focus on physical organic chemistry, which deals with the structure

Mather, Patrick T.

25

Interstellar Organic Chemistry  

Microsoft Academic Search

Complex organic molecules that are stable against radiation may pervade interstellar space, with their degradation products a source of those molecules observed. The connexion between biological and interstellar organic chemistry is, however, analogical rather than substantive, and the prospect for interstellar biology is dim. This article is based on Professor Sagan's contribution to a symposium at the National Radio Astronomy

Carl Sagan

1972-01-01

26

Exploring Atmospheric Aqueous Chemistry (and Secondary Organic Aerosol Formation) through OH Radical Oxidation Experiments, Droplet Evaporation and Chemical Modeling  

NASA Astrophysics Data System (ADS)

Gas phase photochemistry fragments and oxidizes organic emissions, making water-soluble organics ubiquitous in the atmosphere. My group and others have found that several water-soluble compounds react further in the aqueous phase forming low volatility products under atmospherically-relevant conditions (i.e., in clouds, fogs and wet aerosols). Thus, secondary organic aerosol can form as a result of gas followed by aqueous chemistry (aqSOA). We have used aqueous OH radical oxidation experiments coupled with product analysis and chemical modeling to validate and refine the aqueous chemistry of glyoxal, methylglyoxal, glycolaldehyde, and acetic acid. The resulting chemical model has provided insights into the differences between oxidation chemistry in clouds and in wet aerosols. Further, we conducted droplet evaporation experiments to characterize the volatility of the products. Most recently, we have conducted aqueous OH radical oxidation experiments with ambient mixtures of water-soluble gases to identify additional atmospherically-important precursors and products. Specifically, we scrubbed water-soluble gases from the ambient air in the Po Valley, Italy using four mist chambers in parallel, operating at 25-30 L min-1. Aqueous OH radical oxidation experiments and control experiments were conducted with these mixtures (total organic carbon ? 100 ?M-C). OH radicals (3.5E-2 ?M [OH] s-1) were generated by photolyzing H2O2. Precursors and products were characterized using electrospray ionization mass spectrometry (ESI-MS), ion chromatography (IC), IC-ESI-MS, and ultra high resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). Chemical modeling suggests that organic acids (e.g., oxalate, pyruvate, glycolate) are major products of OH radical oxidation at cloud-relevant concentrations, whereas organic radical - radical reactions result in the formation of oligomers in wet aerosols. Products of cloud chemistry and droplet evaporation have effective vapor pressures that are orders of magnitude lower when ammonium hydroxide is present (pH 7) than without (at lower pH). In Po Valley experiments, nitrogen-containing organics were prominent precursors and intermediates. Pyruvate and oxalate were among the products. Importantly, formation of aqSOA helps to explain the high O/C ratios found in atmospheric aerosols. While uncertainties remain large, global modeling suggests that aqSOA is comparable in magnitude to SOA formed through gas phase chemistry and vapor pressure driven partitioning (gasSOA).

Turpin, B. J.; Kirkland, J. R.; Lim, Y. B.; Ortiz-Montalvo, D. L.; Sullivan, A.; Häkkinen, S.; Schwier, A. N.; Tan, Y.; McNeill, V. F.; Collett, J. L.; Skog, K.; Keutsch, F. N.; Sareen, N.; Carlton, A. G.; Decesari, S.; Facchini, C.

2013-12-01

27

Virtual Chemistry Experiments  

NSDL National Science Digital Library

Chemistry applets simulate various experiments, apparatus, and chemical processes. The display and operation of an applet can be controlled by the user through the PARAM options in the APPLET tag and through JavaScript commands.

David N. Blauch

28

Online organic chemistry  

NASA Astrophysics Data System (ADS)

This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online office hours were found to be effective, and discussion sessions can be placed online as well. A model was created that explains 36.1% of student performance based on GPA, ACT Math score, grade in previous chemistry course, and attendance at various forms of discussion. Online exams have been created which test problem-solving skills and is instantly gradable. In these exams, students can submit answers until time runs out for different numbers of points. These facets were combined effectively to create an entirely online organic chemistry course which students prefer over the in-person alternative. Lastly, there is a vision for where online organic chemistry is going and what can be done to improve education for all.

Janowicz, Philip A.

29

The Birthday of Organic Chemistry.  

ERIC Educational Resources Information Center

Describes how the synthesis of urea, 150 years ago, was a major factor in breaking the artificial barrier that existed between organic and inorganic chemistry, and this contributed to the rapid growth of organic chemistry. (GA)

Benfey, Otto Theodor; Kaufman, George B.

1979-01-01

30

The Separation and Identification of Two Unknown Solid Organic Compounds: An Experiment for the Sophomore Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

Segregation and recognition of two unfamiliar concrete organic compounds are achieved through microscale flash chromatography and spectroscopy plus melting point verifications respectively. This inexpensive and harmless microscale experiment for sophomore students ensures exercise in chromatographic and spectroscopic methods.

Feist, Patty L.

2004-01-01

31

An NMR Study of Isotope Effect on Keto-Enol Tautomerization: A Physical Organic Chemistry Experiment  

ERIC Educational Resources Information Center

Isotope substitution often affects the rate of an organic reaction and can be used to reveal the underlying mechanism. A series of experiments that use (super 1)H NMR to determine primary and secondary isotope effects, activation parameters, and the regioselectivity of butanone enolization are described.

Atkinson, D.; Chechik, V.

2004-01-01

32

Enantiomeric Resolution of [Plus or Minus] Mandelic Acid by (1R,2S)-(--)-Ephedrine: An Organic Chemistry Laboratory Experiment Illustrating Stereoisomerism  

ERIC Educational Resources Information Center

The experiment involving enantiomeric resolution, as an illustration of chiral technology, is an excellent early organic chemistry lab experiment. The success of this enantiomeric resolution can be judged by melting point, demonstrated by [plus or minus]-mandelic acid-(1R,2S)-(--)-ephedrine system.

Baar, Marsha R.; Cerrone-Szakal, Andrea L.

2005-01-01

33

Organic Chemistry and Your Cellphone  

NSDL National Science Digital Library

The National Center for Case Study Teaching in Science releases new and helpful teaching materials on a regular basis. This recent addition to the Center's great resources deals with organic chemistry and cellphones. Crafted by Courtney Meyet and Richard Hooley of the University of California, Riverside, this case study guides students "through a systematic exploration of the synthesis and properties of polyphenylene vinylene." The whole experience starts with a classic article from Nature magazine and includes a PowerPoint presentation, a series of group questions, and other activities. The resources here are intended for an undergraduate audience and persons with an interest in organic reactions, organic materials, and polymers will find that this resource is most efficacious.

Hooley, Richard J.

2013-09-16

34

Mars aqueous chemistry experiment  

NASA Technical Reports Server (NTRS)

The Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. Progress for the first year MACE PIDDP is reported in two major areas of effort: (1) fluids handling concepts, definition, and breadboard fabrication and (2) aqueous chemistry ion sensing technology and test facility integration. A fluids handling breadboard was designed, fabricated, and tested at Mars ambient pressure. The breadboard allows fluid manipulation scenarios to be tested under the reduced pressure conditions expected in the Martian atmosphere in order to validate valve operations, orchestrate analysis sequences, investigate sealing integrity, and to demonstrate efficacy of the fluid handling concept. Additional fluid manipulation concepts have also been developed based on updated MESUR spacecraft definition. The Mars Aqueous Chemistry Experiment Ion Selective Electrode (ISE) facility was designed as a test bed to develop a multifunction interface for measurements of chemical ion concentrations in aqueous solution. The interface allows acquisition of real time data concerning the kinetics and heats of salt dissolution, and transient response to calibration and solubility events. An array of ion selective electrodes has been interfaced and preliminary calibration studies performed.

Clark, Benton C.; Mason, Larry W.

1993-01-01

35

Determination of the Absolute Stereochemistry of Secondary Alcohols: An Advanced Organic Chemistry Experiment for Undergraduate Students.  

ERIC Educational Resources Information Center

Describes experiments which can be completed in five four-hour laboratory sessions, including two synthesis (alpha-phenylbutyric and alpha-phenylbutyric acid anhydride) and determining the absolute stereochemistry of secondary alcohols using the synthetic products. (JN)

Bandaranayake, Wickramasinghe M.

1980-01-01

36

Synthesis of Chemiluminescent Esters: A Combinatorial Synthesis Experiment for Organic Chemistry Students  

ERIC Educational Resources Information Center

A group of techniques aimed at synthesizing a large number of structurally diverse compounds is called combinatorial synthesis. Synthesis of chemiluminescence esters using parallel combinatorial synthesis and mix-and-split combinatorial synthesis is experimented.

Duarte, Robert; Nielson, Janne T.; Dragojlovic, Veljko

2004-01-01

37

Detection of Salicylic Acid in Willow Bark: An Addition to a Classic Series of Experiments in the Introductory Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

Salicylic acid and its derivative, acetylsalicylic acid, are often encountered in introductory organic chemistry experiments, and mention is often made that salicylic acid was originally isolated from the bark of the willow tree. This biological connection, however, is typically not further pursued, leaving students with an impression that biology…

Clay, Matthew D.; McLeod, Eric J.

2012-01-01

38

Organic Chemistry for the Gifted.  

ERIC Educational Resources Information Center

In response to a serious shortage of chemists in South Africa, gifted secondary school students are enrolled in an enrichment program in organic chemistry and encouraged to consider chemistry or one of its related fields as a career. The introductory portion of the program involves approximately 90 hours over a 3-year period while the advanced…

deBeer, W. H. J.

39

Evaluating Mechanisms of Dihydroxylation by Thin-Layer Chromatography: A Microscale Experiment for Organic Chemistry  

ERIC Educational Resources Information Center

A microscale experiment is presented in which cyclohexene is dihydroxylated under three sets of conditions: epoxidation-hydrolysis, permanganate oxidation, and the Woodward dihydroxylation. The products of the reactions are determined by the use of thin-layer chromatography. Teams of students are presented with proposed mechanisms for each…

Burlingham, Benjamin T.; Rettig, Joseph C.

2008-01-01

40

Mars aqueous chemistry experiment  

NASA Technical Reports Server (NTRS)

Mars Aqueous Chemistry Experiment (MACE) is designed to conduct a variety of measurements on regolith samples, encompassing mineral phase analyses, chemical interactions with H2O, and physical properties determinations. From these data, much can be learned or inferred regarding the past weathering environment, the contemporaneous soil micro-environments, and the general chemical and physical state of the Martian regolith. By analyzing both soil and duricrust samples, the nature of the latter may become more apparent. Sites may be characterized for comparative purposes and criteria could be set for selection of high priority materials on future sample return missions. The second year of the MACE project has shown significant progress in two major areas. MACE Instrument concept definition is a baseline design that has been generated for the complete MACE instrument, including definition of analysis modes, mass estimates and thermal model. The design includes multiple reagent reservoirs, 10 discrete analysis cells, sample manipulation capability, and thermal control. The MACE Measurement subsystems development progress is reported regarding measurement capabilities for aqueous ion sensing, evolved gas sensing, solution conductivity measurement, reagent addition (titration) capabilities, and optical sensing of suspended particles.

Clark, Benton C.; Mason, Larry W.

1994-01-01

41

Titan's organic chemistry  

Microsoft Academic Search

Voyager discovered nine simple organic molecules in the atmosphere of Titan. Complex organic solids, called tholins, produced by irradiation of the simulated Titanian atmosphere, are consistent with measured properties of Titan from ultraviolet to microwave frequencies and are the likely main constituents of the observed red aerosols. The tholins contain many of the organic building blocks central to life on

C. Sagan; W. R. Thompson; B. N. Khare

1985-01-01

42

Titan's organic chemistry  

NASA Astrophysics Data System (ADS)

Voyager discovered nine simple organic molecules in the atmosphere of Titan. Complex organic solids, called tholins, produced by irradiation of the simulated Titanian atmosphere, are consistent with measured properties of Titan from ultraviolet to microwave frequencies and are the likely main constituents of the observed red aerosols. The tholins contain many of the organic building blocks central to life on earth. At least 100-m, and possibly kms thicknesses of complex organics have been produced on Titan during the age of the solar system, and may exist today as submarine deposits beneath an extensive ocean of simple hydrocarbons.

Sagan, C.; Thompson, W. R.; Khare, B. N.

43

Soil Organic Chemistry.  

ERIC Educational Resources Information Center

A brief review is presented of some of the organic compounds and reactions that occur in soil. Included are nitrogenous compounds, compounds of phosphorus and sulfur, carbohydrates, phenolic compounds, and aliphatic acids. (BB)

Anderson, G.

1979-01-01

44

Chemistry 685 (CHE 685) Advanced Organic Chemistry: Organic Reaction Mechanisms and Molecular Interactions  

E-print Network

Chemistry 685 (CHE 685) Advanced Organic Chemistry: Organic Reaction Mechanisms and Molecular and physical chemistry Course description and rationale CHE685 is a graduate-level organic chemistry course. These two courses focus on physical organic chemistry, which deals with the structure and reactivity

Mather, Patrick T.

45

Radiation Chemistry in Organized Assemblies.  

ERIC Educational Resources Information Center

Expands the basic concepts regarding the radiation chemistry of simple aqueous systems to more complex, but well defined, organized assemblies. Discusses the differences in behavior in comparison to simple systems. Reviews these techniques: pulse radiolysis, laser flash, photolysis, and steady state irradiation by gamma rays or light. (CS)

Thomas, J. K.; Chen, T. S.

1981-01-01

46

Titan: a laboratory for prebiological organic chemistry.  

PubMed

When we examine the atmospheres of the Jovian planets (Jupiter, Saturn, Uranus, and Neptune), the satellites in the outer solar system, comets, and even--through microwave and infrared spectroscopy--the cold dilute gas and grains between the stars, we find a rich organic chemistry, presumably abiological, not only in most of the solar system but throughout the Milky Way galaxy. In part because the composition and surface pressure of the Earth's atmosphere 4 x 10(9) years ago are unknown, laboratory experiments on prebiological organic chemistry are at best suggestive; but we can test our understanding by looking more closely at the observed extraterrestrial organic chemistry. The present Account is restricted to atmospheric organic chemistry, primarily on the large moon of Saturn. Titan is a test of our understanding of the organic chemistry of planetary atmospheres. Its atmospheric bulk composition (N2/CH4) is intermediate between the highly reducing (H2/He/CH4/NH3/H2O) atmospheres of the Jovian planets and the more oxidized (N2/CO2/H2O) atmospheres of the terrestrial planets Mars and Venus. It has long been recognized that Titan's organic chemistry may have some relevance to the events that led to the origin of life on Earth. But with Titan surface temperatures approximately equal to 94 K and pressures approximately equal to 1.6 bar, the oceans of the early Earth have no ready analogue on Titan. Nevertheless, tectonic events in the water ice-rich interior or impact melting and slow re-freezing may lead to an episodic availability of liquid water. Indeed, the latter process is the equivalent of a approximately 10(3)-year-duration shallow aqueous sea over the entire surface of Titan. PMID:11537156

Sagan, C; Thompson, W R; Khare, B N

1992-01-01

47

Experiments in Electroanalytical Chemistry  

NSDL National Science Digital Library

This website offers educators a set of eight classical electroanalytical experiments suitable for use in a quantitative analysis, instrumental analysis, or electrochemistry course. The materials should be useful for advanced undergraduates and beginning graduate students. Experiments include coulometric, conductometric, and potentiometric titrations, stripping analysis, flow injection analysis, and polarography. It is important to note that several of the experiments use mercury or mercury coated electrodes which present safety concerns.

48

Using Artificial Soil and Dry-Column Flash Chromatography to Simulate Organic Substance Leaching Process: A Colorful Environmental Chemistry Experiment  

ERIC Educational Resources Information Center

Soil is an important and complex environmental compartment and soil contamination contributes to the pollution of aquifers and other water basins. A simple and low-cost experiment is described in which the mobility of three organic compounds in an artificial soil is examined using dry-column flash chromatography. The compounds were applied on top…

de Avellar, Isa G. J.; Cotta, Tais A. P. G.; Neder, Amarilis de V. Finageiv

2012-01-01

49

Headspace GC-MS Analysis of Halogenated Volatile Organic Compounds in Aqueous Samples: An Experiment for General Chemistry Laboratory  

ERIC Educational Resources Information Center

Analysis of halogenated volatile organic compounds (HVOCs) by GC-MS demonstrates the use of instrumentation in the environmental analysis of pollutant molecules and enhances student understanding of stable isotopes in nature. In this experiment, students separated and identified several HVOCs that have been implicated as industrial groundwater…

Keller, John W.; Fabbri, Cindy E.

2012-01-01

50

Hydrothermal organic synthesis experiments  

NASA Technical Reports Server (NTRS)

The serious scientific debate about spontaneous generation which raged for centuries reached a climax in the nineteenth century with the work of Spallanzani, Schwann, Tyndall, and Pasteur. These investigators demonstrated that spontaneous generation from dead organic matter does not occur. Although no aspects of these experiments addressed the issue of whether organic compounds could be synthesized abiotically, the impact of the experiments was great enough to cause many investigators to assume that life and its organic compounds were somehow fundamentally different than inorganic compounds. Meanwhile, other nineteenth-century investigators were showing that organic compounds could indeed be synthesized from inorganic compounds. In 1828 Friedrich Wohler synthesized urea in an attempt to form ammonium cyanate by heating a solution containing ammonia and cyanic acid. This experiment is generally recognized to be the first to bridge the artificial gap between organic and inorganic chemistry, but it also showed the usefulness of heat in organic synthesis. Not only does an increase in temperature enhance the rate of urea synthesis, but Walker and Hambly showed that equilibrium between urea and ammonium cyanate was attainable and reversible at 100 C. Wohler's synthesis of urea, and subsequent syntheses of organic compounds from inorganic compounds over the next several decades dealt serious blows to the 'vital force' concept which held that: (1) organic compounds owe their formation to the action of a special force in living organisms; and (2) forces which determine the behavior of inorganic compounds play no part in living systems. Nevertheless, such progress was overshadowed by Pasteur's refutation of spontaneous generation which nearly extinguished experimental investigations into the origins of life for several decades. Vitalism was dealt a deadly blow in the 1950's with Miller's famous spark-discharge experiments which were undertaken in the framework of the Oparin and Haldane hypotheses concerning the origin of life. These hypotheses were constructed on some basic assumptions which included a reduced atmosphere, and a low surface temperature for the early Earth. These ideas meshed well with the prevailing hypothesis of the 1940's and 50's that the Earth had formed through heterogeneous accretion of dust from a condensing solar nebula. Miller's experiments were extremely successful, and were followed by numerous other experiments by various investigators who employed a wide variety of energy sources for abiotic synthesis including spark discharges, ultra-violet radiation, heat, shock waves, plasmas, gamma rays, and other forms of energy. The conclusion reached from this body of work is that energy inputs can drive organic synthesis from a variety of inorganic starting materials.

Shock, Everett L.

1992-01-01

51

Chemistry: Experiments, Demonstrations and Other Activities Suggested for Chemistry.  

ERIC Educational Resources Information Center

This publication is a handbook used in conjunction with the course of study in chemistry developed through the New York State Education Department and The University of the State of New York. It contains experiments, demonstrations, and other activities for a chemistry course. Areas covered include the science of chemistry, the atomic structure of…

New York State Education Dept., Albany. Bureau of Secondary Curriculum Development.

52

Caring for the Environment while Teaching Organic Chemistry  

ERIC Educational Resources Information Center

A comprehensive program in the field of green chemistry, which concentrates on processing and managing of wastes produced during laboratory experiments, is presented. The primary aim of the program is to instill a sense of responsibility and a concern for the environment through organic chemistry education.

Santos, Elvira Santos; Gavilan Garcia, Irma Cruz; Lejarazo Gomez, Eva Florencia

2004-01-01

53

5.13 Organic Chemistry II, Spring 2003  

E-print Network

Intermediate organic chemistry. Synthesis, structure determination, mechanism, and the relationships between structure and reactivity emphasized. Special topics in organic chemistry included to illustrate the role of organic ...

Swager, Timothy Manning

54

5.13 Organic Chemistry II, Fall 2003  

E-print Network

Intermediate organic chemistry. Synthesis, structure determination, mechanism, and the relationships between structure and reactivity emphasized. Special topics in organic chemistry included to illustrate the role of organic ...

Jamison, Timothy F.

55

Chemistry Experiment Simulation, Tutorials and Computer Animations for College Chemistry  

NSDL National Science Digital Library

This page from Iowa State University includes a number of simulations and animations for introductory level college chemistry courses. Topics include electrochemistry, redox titration, thermochemistry, general equilibria, acid-base equilibria, stoichiometry, kinetics, predicting the products of chemical reactions in organic chemistry and understanding fundamental concepts of periodic trends and chemical bonding. After reading instructions on what computer programs will be needed, users can simulate chemical processes related to electrochemistry, acid-base chemistry & stoichiometry.

Greenbowe, Tom

56

Interdisciplinary Chemistry Experiment: An Environmentally Friendly Extraction of Lycopene  

ERIC Educational Resources Information Center

A novel experiment for the extraction of lycopene from tomato paste without the use of an organic solvent is described. The experiment employs polymer, green, and analytical chemistry. This environmentally friendly extraction is more efficient and requires less time than the traditional approach using an organic solvent. The extraction is…

Zhu, Jie; Zhang, Mingjie; Liu, Qingwei

2008-01-01

57

Synthesis of Aspirin: A General Chemistry Experiment  

NASA Astrophysics Data System (ADS)

An experiment is described that is suitable for the early portion of the laboratory in a general chemistry course and integrates organic examples. It is the two-step synthesis of aspirin starting from oil of wintergreen. The mechanism for this synthesis provides examples of three major classes of chemical reactions: hydrolysis, condensation, and proton transfer. To understand the chemistry, the student must be able to recognize the common molecular framework shared by oil of wintergreen, salicylic acid, and aspirin and to identify the -OH and -CO2 sites where chemical changes occur. The experiment differs in three ways from traditional aspirin synthesis experiments for general chemistry. It is designed to be performed early rather than late; it starts from a naturally occurring material and requires two steps rather than one; and it utilizes FTIR spectroscopy to distinguish among oil of wintergreen starting material, salicylic acid intermediate, and aspirin product. The use of FTIR spectroscopy introduces students to a modern analytical technique that is currently used in research involving aspirin.

Olmsted, John A., III

1998-10-01

58

Chemistry of secondary organic aerosol formation  

NASA Astrophysics Data System (ADS)

The photooxidation of volatile organic compounds (VOCs) in the atmosphere can lead to the formation of secondary organic aerosol (SOA), a major component of fine particulate matter. Improvements to air quality require insight into the many reactive intermediates that lead to SOA formation, of which only a small fraction have been measured at the molecular level. This thesis describes the chemistry of secondary organic aerosol (SOA) formation from several atmospherically relevant hydrocarbon precursors. Photooxidation experiments of methoxyphenol and phenolic compounds and C12 alkanes were conducted in the Caltech Environmental Chamber. These experiments include the first photooxidation studies of these precursors run under sufficiently low NOx levels, such that RO2 + HO2 chemistry dominates, an important chemical regime in the atmosphere. Using online Chemical Ionization Mass Spectrometery (CIMS), key gas-phase intermediates that lead to SOA formation in these systems were identified. With complementary particle-phase analyses, chemical mechanisms elucidating the SOA formation from these compounds are proposed. Three methoxyphenol species (phenol, guaiacol, and syringol) were studied to model potential photooxidation schemes of biomass burning intermediates. SOA yields (ratio of mass of SOA formed to mass of primary organic reacted) exceeding 25% are observed. Aerosol growth is rapid and linear with the organic conversion, consistent with the formation of essentially non-volatile products. Gas and aerosol-phase oxidation products from the guaiacol system show that the chemical mechanism consists of highly oxidized aromatic species in the particle phase. Syringol SOA yields are lower than that of phenol and guaiacol, likely due to unique chemistry dependent on methoxy group position. The photooxidation of several C12 alkanes of varying structure n-dodecane, 2-methylundecane, cyclododecane, and hexylcyclohexane) were run under extended OH exposure to investigate the effect of molecular structure on SOA yields and photochemical aging. Peroxyhemiacetal formation from the reactions of several multifunctional hydroperoxides and aldehyde intermediates was found to be central to organic growth in all systems, and SOA yields increased with cyclic character of the starting hydrocarbon. All of these studies provide direction for future experiments and modeling in order to lessen outstanding discrepancies between predicted and measured SOA.

Yee, Lindsay Diana

59

Abiotic Organic Chemistry in Hydrothermal Systems.  

NASA Astrophysics Data System (ADS)

Abiotic organic chemistry in hydrothermal systems is of interest to biologists, geochemists and oceanographers. This chemistry consists of thermal alteration of organic matter and minor prebiotic synthesis of organic compounds. Thermal alteration has been extensively documented to yield petroleum and heavy bitumen products from contemporary organic detritus. Carbon dioxide, carbon monoxide, ammonia and sulfur species have been used as precursors in prebiotic synthesis experiments to organic compounds. These inorganic species are common components of hot spring gases and marine hydrothermal systems. It is of interest to further test their reactivities in reductive aqueous thermolysis. We have synthesized organic compounds (lipids) in aqueous solutions of oxalic acid, and with carbon disulfide or ammonium bicarbonate at temperatures from 175-400° C. The synthetic lipids from oxalic acid solutions consisted of n-alkanols, n-alkanoic acids, n-alkyl formates, n-alkanones, n-alkenes and n-alkanes, typically to C30 with no carbon number preferences. The products from CS2 in acidic aqueous solutions yielded cyclic thioalkanes, alkyl polysulfides, and thioesters with other numerous minor compounds. The synthesis products from oxalic acid and ammonium bicarbonate solutions were homologous series of n-alkyl amides, n-alkyl amines, n-alkanes and n-alkanoic acids, also to C30 with no carbon number predominance. Condensation (dehydration) reactions also occur under elevated temperatures in aqueous medium as tested by model reactions to form amide, ester and nitrile bonds. It is concluded that the abiotic formation of aliphatic lipids, condensation products (amides, esters, nitriles, and CS2 derivatives (alkyl polysulfides, cyclic polysulfides) is possible under hydrothermal conditions and warrants further studies.

Simoneit, B. R.; Rushdi, A. I.

2004-12-01

60

A Discovery Chemistry Experiment on Buffers  

ERIC Educational Resources Information Center

The Holy Cross Chemistry Department has designed and implemented an experiment on buffers as part of our Discovery Chemistry curriculum. The pedagogical philosophy of Discovery Chemistry is to make the laboratory the focal point of learning for students in their first two years of undergraduate instruction. We first pose questions in prelaboratory…

Kulevich, Suzanne E.; Herrick, Richard S.; Mills, Kenneth V.

2014-01-01

61

Customized Laboratory Experience in Physical Chemistry  

ERIC Educational Resources Information Center

A new physical chemistry laboratory experience has been designed for upper-level undergraduate chemistry majors. Students customize the first 10 weeks of their laboratory experience by choosing their own set of experiments (from a manual of choices) and setting their own laboratory schedule. There are several topics presented in the accompanying…

Castle, Karen J.; Rink, Stephanie M.

2010-01-01

62

Preparation, Characterization, and Postsynthetic Modification of Metal-Organic Frameworks: Synthetic Experiments for an Undergraduate Laboratory Course in Inorganic Chemistry  

ERIC Educational Resources Information Center

Metal-organic frameworks (MOFs) are crystalline materials that are composed of an infinite array of metal nodes (single ions or clusters) linked to one another by polyfunctional organic compounds. Because of their extraordinary surface areas and high degree of control over the physical and chemical properties, these materials have received much…

Sumida, Kenji; Arnold, John

2011-01-01

63

CHEMISTRY 324W ORGANIC LABORATORY  

E-print Network

office for about $3.00 (our cost). Recommended Materials: USB memory stick for backing up data and text for multiple chemistry classes) $5 key deposit fee (refunded at end of semester with return of key) Course

Wagner, Diane

64

Newer Reagents in Preparative Organic Chemistry.  

ERIC Educational Resources Information Center

Outlined is the development and use of oxidants for use in elementary organic chemistry classes. Discussed is the oxidation of alcohols to carbonyl compounds, and the oxidation of primary alcohols or aldehydes to carboxylic acids. (CW)

Grundy, J.

1990-01-01

65

Oxidation of Borneol to Camphor Using Oxone and Catalytic Sodium Chloride: A Green Experiment for the Undergraduate Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

A new green oxidation procedure was developed for the undergraduate organic teaching laboratories using Oxone and a catalytic quantity of sodium chloride for the conversion of borneol to camphor. This simple 1 h, room temperature reaction afforded high quality and yield of product, was environmentally friendly, and produced negligible quantities…

Lang, Patrick T.; Harned, Andrew M.; Wissinger, Jane E.

2011-01-01

66

Acid-Catalyzed Preparation of Biodiesel from Waste Vegetable Oil: An Experiment for the Undergraduate Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

This undergraduate organic laboratory exercise involves the sulfuric acid-catalyzed conversion of waste vegetable oil into biodiesel. The acid-catalyzed method, although inherently slower than the base-catalyzed methods, does not suffer from the loss of product or the creation of emulsion producing soap that plagues the base-catalyzed methods when…

Bladt, Don; Murray, Steve; Gitch, Brittany; Trout, Haylee; Liberko, Charles

2011-01-01

67

Mars Aqueous Chemistry Experiment (MACE)  

NASA Technical Reports Server (NTRS)

The concept of an aqueous-based chemical analyzer for Martian surface materials has been demonstrated to be feasible. During the processes of analysis, design, breadboarding, and most importantly, testing, it has become quite apparent that there are many challenges in implementing such a system. Nonetheless, excellent progress has been made and a number of problems which arose have been solved. The ability to conduct this work under a development environment which is separate and which precedes the project-level development has allowed us to find solutions to these implementation realities at low cost. If the instrument had been selected for a mission without this laboratory pre-project work, the costs of implementation would be much higher. In the four areas covered in Sections D, E, F, and G of this Final Report, outstanding progress has been made. There still remains the task of flight-qualifying certain of the components. This is traditionally done under the aegis of a Flight Project, but just as the concept development can be done at much lower cost when kept small and focused, so could the qualification program of critical parts benefit. We recommend, therefore, that NASA consider means of such qualifications and brass-boarding, in advance of final flight development. This is a generic recommendation, but hardware such as the Mars aqueous chemistry experiment (MACE) and other similarly-new concepts are particularly applicable. MACE now has wide versatility, in being able to reliably dispense both liquids and solids as chemical reagents to an entire suite of samples. The hardware and the experiment is much simpler than was developed for the Viking Biology instrument, yet can accomplish all the inorganic chemical measurements that the Viking desing was capable of. In addition, it is much more flexible and versatile to new experiment protocols (and reagents) than the Viking design ever could have been. MACE opens up the opportunity for many different scientific disciplines to design sub- experiments and to benefit from the investigations that can be conducted. In this sense, it will have the value of a facility, although our recommendation would be that it be under the stewardship of a single lead investigator to insure that conflicting requirements not compromise the straight-forward design that have been achieved. MACE is an excellent candidate for upcoming Mars missions, including the Mars Surveyor Program (MSP) lander missions in 2001 and 2003. In addition, it could be used for any mission to the surface of any other planet or planetary body (including small bodies). An important next step is to encourage various investigators to propose specific uses for this experiment that specifically address their major scientific objectives for upcoming missions.

Benton, Clark C. (Editor)

1995-01-01

68

Analysis of Bromination of Ethylbenzene Using a 45 MHz NMR Spectrometer: An Undergraduate Organic Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

A 45 MHz benchtop NMR spectrometer is used to identify the structures and determine the amount of 1-bromoethylbenzene and 1,1-dibromoethylbenzene produced from free-radical bromination of ethylbenzene. The experiment is designed for nonchemistry majors, specifically B.S. Biology students, in a predominantly undergraduate institution with…

Isaac-Lam, Meden F.

2014-01-01

69

Preparation of a N-Heterocyclic Carbene Nickel(II) Complex: Synthetic Experiments in Current Organic and Organometallic Chemistry  

ERIC Educational Resources Information Center

A four-part experiment that leads to the synthesis of a cyclopentadienyl chloro-nickel(II) complex bearing a N-heterocyclic carbene (NHC) ligand is presented. In the first part, the preparation of 1,3-bis-(2,4,6-trimethylphenyl)imidazolium chloride (IMes[middle dot]HCl) in a one-pot procedure by reaction of 2,4,6-trimethylaniline with…

Ritleng, Vincent; Brenner, Eric; Chetcuti, Michael J.

2008-01-01

70

A Discovery-Based Experiment Involving Rearrangement in the Conversion of Alcohols to Alkyl Halides: Permanent Magnet [to the thirteenth power]C NMR in the First-Semester Organic Chemistry Lab  

ERIC Educational Resources Information Center

The use of permanent magnet [to the thirteenth power]C NMR in large-section first-semester organic chemistry lab courses is limited by the availability of experiments that not only hinge on first-semester lecture topics, but which also produce at least 0.5 mL of neat liquid sample. This article reports a discovery-based experiment that meets both…

Kjonaas, Richard A.; Tucker, Ryand J. F.

2008-01-01

71

The role of organic complexation on ambient iron chemistry in the equatorial Pacific Ocean and the response of a mesoscale iron addition experiment  

Microsoft Academic Search

We participated on the Iron-Ex II study in the equatorial Pacific to investigate ambient iron chemistry and its response to a mesoscale iron addition experiment. As expected, dissolved iron values in the high-nutrient, low- chlorophyll surface waters of the South Equatorial Current (4-6\\

Eden L. Rue

1997-01-01

72

Nobel Chemistry in the Laboratory: Synthesis of a Ruthenium Catalyst for Ring-Closing Olefin Metathesis--An Experiment for the Advanced Inorganic or Organic Laboratory  

ERIC Educational Resources Information Center

An experiment for the upper-level undergraduate laboratory is described in which students synthesize a ruthenium olefin metathesis catalyst, then use the catalyst to carry out the ring-closing metathesis of diethyl diallylmalonate. The olefin metathesis reaction was the subject of the 2005 Nobel Prize in chemistry. The catalyst chosen for this…

Greco, George E.

2007-01-01

73

BOMC LabBOMC Lab (Bio(Bio--Organic Materials Chemistry)Organic Materials Chemistry)  

E-print Network

BOMC LabBOMC Lab (Bio(Bio--Organic Materials Chemistry)Organic Materials Chemistry) FORTHFORTHSystems BioBio--PolymerPolymer HybridHybrid SystemsSystems PolymericPolymeric Particles &Particles & Thin. Phys. A 2008 #12;BioBio--PolymerPolymer NanoreactorsNanoreactors #12;BioBio--Polymer Hybrid Systems

Jonas, Ulrich - Institute of Electronic Structure and Laser, Foundation for Research and Technology

74

Hydrothermal organic synthesis experiments  

NASA Technical Reports Server (NTRS)

Ways in which heat is useful in organic synthesis experiments are described, and experiments on the hydrothermal destruction and synthesis of organic compounds are discussed. It is pointed out that, if heat can overcome kinetic barriers to the formation of metastable states from reduced or oxidized starting materials, abiotic synthesis under hydrothermal conditions is a distinct possibility. However, carefully controlled experiments which replicate the descriptive variables of natural hydrothermal systems have not yet been conducted with the aim of testing the hypothesis of hydrothermal organic systems.

Shock, Everett L.

1992-01-01

75

Using Ozone in Organic Chemistry Lab: The Ozonolysis of Eugenol  

ERIC Educational Resources Information Center

An ozonolysis experiment, suitable for undergraduate organic chemistry lab, is presented. Ozonolysis of eugenol (clove oil), followed by reductive workup furnishes an aldehyde that is easily identified by its NMR and IR spectra. Ozone (3-5% in oxygen) is produced using an easily built generator. (Contains 2 figures and 1 scheme.)

Branan, Bruce M.; Butcher, Joshua T.; Olsen, Lawrence R.

2007-01-01

76

Medical Mycology and the Chemistry Classroom: Germinating Student Interest in Organic Chemistry  

ERIC Educational Resources Information Center

Efforts to provide active research context to introductory courses in basic sciences are likely to better engage learners and provide a framework for relevant concepts. A simple teaching and learning experiment was conducted to use concepts in organic chemistry to solve problems in the life sciences. Bryant University is a liberal arts university…

Bliss, Joseph M.; Reid, Christopher W.

2013-01-01

77

CHEMISTRY 324W Fall 2010 ORGANIC LABORATORY  

E-print Network

by appointment, or drop-in. Teaching Assistant..Zhipeng Dai Required Materials: (1) PAVIA et al. , MICROSCALE $120 (2) chemistry computer lab fee $45 (charged only once for multiple chem classes) (3) key deposit is typically used in a given reaction is provided. Organic Synthesis; collective volumes 1-5 (John Wiley

Wagner, Diane

78

Analytical Chemistry Role Playing Experiments  

NSDL National Science Digital Library

This page features a number of laboratory experiments (available for download in PDF format) which allow students the opportunity to role play in groups to solve problems. Experiments involve titrations, gravimetry, atomic absorption, chromatography.

2011-04-14

79

Experiments in the Chemistry of Food.  

ERIC Educational Resources Information Center

This booklet presents 18 experiments in the chemistry of food, suitable for elementary and secondary school science classes. Experiments deal with an analysis of milk, determinations of the amounts of sulfur dioxide, iron, and fat in foods, and the concentration of vitamin C in fruit juice and iodine in salt. Tests are provided for fats,…

Weaver, Elbert C.

80

Purdue University: Division of Organic Chemistry  

NSDL National Science Digital Library

Purdue University created this website to promote its organic chemistry department's diverse research initiatives. This expansive website provides links to materials on twelve of the faculty's chemistry research groups. Research includes NMR imaging of micellar solutions, hydride fuel cell examinations, dimerization inhibitors of transcription factors, and gas phase synthesis. Users can find lists of the many publications and view images and photos of the division's work and facilities. Visitors can learn about the many instruments used by the division such as mass spectrometry, continuously rotated cellular reactor, and an ozone generator.

81

Teaching Introductory Organic Chemistry: 'Blooming' beyond a Simple Taxonomy  

NASA Astrophysics Data System (ADS)

Undergraduate students often experience fear and trepidation when studying introductory organic chemistry: the majority of these students use a memorization approach to the material, sacrificing understanding. This paper describes one way the problem can be resolved. The cognitive working level we emphasize in our teaching practice involves making the necessary connections between the general chemistry principles that students have learned (or at least have been exposed to in their senior high school years and have revisited again in their university freshman year) and the many reactions and mechanisms they will encounter in organic chemistry. Educating students early in the course about the various levels of the cognitive process and the necessary working level of cognition for success in organic chemistry teaches connections between the general chemistry principles and reaction mechanisms. This empowers students to approach the subject from a perspective of understanding rather than memorization, and replaces fear and trepidation with confidence. In addition, this can help narrow the gap between what instructors expect from their students and what their students think is sufficient to master the course content.

Pungente, Michael D.; Badger, Rodney A.

2003-07-01

82

Experiments for Modern Introductory Chemistry.  

ERIC Educational Resources Information Center

Presents a headspace gas chromatography experiment that enables discovery of the temperature dependence of the vapor pressure of a pure liquid. Illustrates liquid-vapor phase equilibrium of pure liquids. Contains 22 references. (JRH)

Kildahl, Nicholas; Berka, Ladislav H.

1995-01-01

83

Synthesis of Aspirin: A General Chemistry Experiment.  

ERIC Educational Resources Information Center

Describes the redesign of the first semester general chemistry laboratory at the college level. An organic component is included in the redesign and it provides students with explicit examples of several types of operations in which chemists engage. Contains 16 references. (DDR)

Olmsted, John III

1998-01-01

84

Organic Chemistry Self Instructional Package 5: Alkanes Preparations and Reactions.  

ERIC Educational Resources Information Center

This booklet, one of a series of 17 developed at Prince George's Community College, Largo, Maryland, provides an individualized, self-paced undergraduate organic chemistry instruction module designed to augment any course in organic chemistry but particularly those taught using the text "Organic Chemistry" by Morrison and Boyd. The entire series…

Zdravkovich, V.

85

Organic Chemistry Self Instructional Package 4: Alkanes-Nomenclature.  

ERIC Educational Resources Information Center

This booklet, one of a series of 17 developed at Prince George's Community College, Largo, Maryland, provides an individualized, self-paced undergraduate organic chemistry instruction module designed to augment any course in organic chemistry but particularly those taught using the text "Organic Chemistry" by Morrison and Boyd. The entire series…

Zdravkovich, V.

86

Organic Chemistry Self Instructional Package 15: Benzene, Aromaticity.  

ERIC Educational Resources Information Center

This booklet, one of a series of 17 developed at Prince George's Community College, Largo, Maryland, provides an individualized, self-paced undergraduate organic chemistry instruction module designed to augment any course in organic chemistry but particularly those taught using the text "Organic Chemistry" by Morrison and Boyd. The entire series…

Zdravkovich, V.

87

Organic Chemistry Self Instructional Package 9: Alkenes-Reactions 1.  

ERIC Educational Resources Information Center

This booklet, one of a series of 17 developed at Prince George's Community College, Largo, Maryland, provides an individualized, self-paced undergraduate organic chemistry instruction module designed to augment any course in organic chemistry but particularly those taught using the text "Organic Chemistry" by Morrison and Boyd. The entire series…

Zdravkovich, V.

88

An Experiment in Forensic Chemistry: The Breathalyzer.  

ERIC Educational Resources Information Center

Describes a simple experiment done in a quantitative analysis course that illustrates the chemistry of the breath alcohol test. Discusses the development and use of the Breathalyzer. Outlines the experimental procedure, along with the appropriate calculations and discussion of the results. (TW)

Timmer, William C.

1986-01-01

89

A Pre-Vacation Chemistry Experiment  

ERIC Educational Resources Information Center

Describes a chemistry experiment appropriate for the day before Christmas vacation. Students prepare candy canes by following a recipe written in chemical terms. This illustrates that food is composed of chemicals and that the processes involved in cooking are chemical and physical changes. (JR)

Gabel, Dorothy; McSweeny, Jean

1973-01-01

90

Organic Chemistry II Syllabus University of Alaska Fairbanks  

E-print Network

it to reaction chemistry. 6. Be able to predict and write mechanisms of reactions based on fundamental concepts of acid/base chemistry (nucleophiles and electrophiles). 7. Know how to build and optimize organic's HyperChem software. Course Goals 1. Know reaction chemistry of major functional groups of organic

Wagner, Diane

91

Form and Function: An Organic Chemistry Module. Teacher's Guide.  

ERIC Educational Resources Information Center

This teacher's guide is designed to provide science teachers with the necessary guidance and suggestions for teaching organic chemistry. In this book, the diverse field of organic chemistry modules is introduced. The material in this book can be integrated with the other modules in a sequence that helps students to see that chemistry is a unified…

Jarvis, Bruce; Mazzocchi, Paul; Hearle, Robert

92

Atmospheric Chemistry Experiment (ACE): Mission overview  

Microsoft Academic Search

SCISAT-1, also known as the Atmospheric Chemistry Experiment (ACE), is a Canadian satellite mission for remote sensing of the Earth's atmosphere. It was launched into low Earth circular orbit (altitude 650 km, inclination 74°) on 12 Aug. 2003. The primary ACE instrument is a high spectral resolution (0.02 cm-1) Fourier Transform Spectrometer (FTS) operating from 2.2 to 13.3 mum (750-4400

P. F. Bernath; C. T. McElroy; M. C. Abrams; C. D. Boone; M. Butler; C. Camy-Peyret; M. Carleer; C. Clerbaux; P.-F. Coheur; R. Colin; P. DeCola; M. DeMazière; J. R. Drummond; D. Dufour; W. F. J. Evans; H. Fast; D. Fussen; K. Gilbert; D. E. Jennings; E. J. Llewellyn; R. P. Lowe; E. Mahieu; J. C. McConnell; M. McHugh; S. D. McLeod; R. Michaud; C. Midwinter; R. Nassar; F. Nichitiu; C. Nowlan; C. P. Rinsland; Y. J. Rochon; N. Rowlands; K. Semeniuk; P. Simon; R. Skelton; J. J. Sloan; M.-A. Soucy; K. Strong; P. Tremblay; D. Turnbull; K. A. Walker; I. Walkty; D. A. Wardle; V. Wehrle; R. Zander; J. Zou

2005-01-01

93

Shock-induced chemistry in organic materials  

SciTech Connect

The combined 'extreme' environments of high pressure, temperature, and strain rates, encountered under shock loading, offer enormous potential for the discovery of new paradigms in chemical reactivity not possible under more benign conditions. All organic materials are expected to react under these conditions, yet we currently understand very little about the first bond-breaking steps behind the shock front, such as in the shock initiation of explosives, or shock-induced reactivity of other relevant materials. Here, I will present recent experimental results of shock-induced chemistry in a variety of organic materials under sustained shock conditions. A comparison between the reactivity of different structures is given, and a perspective on the kinetics of reaction completion under shock drives.

Dattelbaum, Dana M [Los Alamos National Laboratory; Sheffield, Steve [Los Alamos National Laboratory; Engelke, Ray [Los Alamos National Laboratory; Manner, Virginia [Los Alamos National Laboratory; Chellappa, Raja [Los Alamos National Laboratory; Yoo, Choong - Shik [WASHINGTON STATE UNIV

2011-01-20

94

Simple Organic Chemistry in the Horsehead Nebula  

NASA Astrophysics Data System (ADS)

We present our latest results on carbon chemistry in the Horsehead nebula, one of the most famous objects in the sky and a unique laboratory to understand the chemistry of interstellar clouds} illuminated by UV radiation} from nearby stars. Photodissociation regions (PDRs) are interesting intermediate media between diffuse and dense dark clouds, thus enabling astrochemists to probe a large variety of physical and chemical processes. In particular, our high resolution astronomical observations show that the Horsehead edge is a realistic template to determine the molecular inventory in PDRs and to investigate the photostability of simple organic molecules}. In this contribution we show that simple carbon chains and rings (CCH, c-C3H2 and C4H) are tightly spatially correlated with each other and with the emission of polycyclic aromatic hydrocarbons (PAHs). We show how molecules such as HCO+ start to be enriched in deuterium (DCO+/HCO+ > 0.02) as the gas cools down in the densest and UV protected prestellar condensations. We also determine the gas phase sulfur abundance in the UV irradiated gas from CS and HCS+ observations and chemical modeling. We finally present the first results of our search of gas phase species with a probable dust grain surface origin (e.g., H2S). We stress the need of well conceived astronomical observations together with models that treat consistently both the photochemistry of simple organic species and the radiative transport of their emission lines.

Goicoechea, J. R.; Pety, J.; Gerin, M.; Hily-Blant, P.; Teyssier, D.; Roueff, E.

2009-12-01

95

Novel Aryne Chemistry in Organic Synthesis  

SciTech Connect

Arynes are among the most intensively studied systems in chemistry. However, many aspects of the chemistry of these reactive intermediates are not well understood yet and their use as reagents in synthetic organic chemistry has been somewhat limited, due to the harsh conditions needed to generate arynes and the often uncontrolled reactivity exhibited by these species. Recently, o-silylaryl triflates, which can generate the corresponding arynes under very mild reaction conditions, have been found very useful in organic synthesis. This thesis describes several novel and useful methodologies by employing arynes, which generate from o-silylaryl triflates, in organic synthesis. An efficient, reliable method for the N-arylation of amines, sulfonamides and carbamates, and the O-arylation of phenols and carboxylic acids is described in Chapter 1. Amines, sulfonamides, phenols, and carboxylic acids are good nucleophiles, which can react with arynes generated from a-silylaryl triflates to afford the corresponding N- and O-arylated products in very high yields. The regioselectivity of unsymmetrical arynes has also been studied. A lot of useful, functional groups can tolerate our reaction conditions. Carbazoles and dibenzofurans are important heteroaromatic compounds, which have a variety of biological activities. A variety of substituted carbazoles and dibenzofwans are readily prepared in good to excellent yields starting with the corresponding o-iodoanilines or o-iodophenols and o-silylaryl triflates by a treatment with CsF, followed by a Pd-catalyzed cyclization, which overall provides a one-pot, two-step process. By using this methodology, the carbazole alkaloid mukonine has been concisely synthesized in a very good yield. Insertion of an aryne into a {sigma}-bond between a nucleophile and an electrophile (Nu-E) should potentially be a very beneficial process from the standpoint of organic synthesis. A variety of substituted ketones and sulfoxides have been synthesized in good yields via the intermolecular C-N {sigma}-bond addition of amides and S-N {sigma}-bond addition of sulfinamides to arynes under mild reaction conditions. The indazole moiety is a frequently found subunit in drug substances with important biological activities. Indazole analogues have been readily synthesized under mild reaction conditions by the [3+2] cycloaddition of a variety of diazo compounds with o-silylaryl triflates in the presence of CsF or TBAF. Polycyclic aromatic and heteroaromatic hydrocarbons have been synthesized in high yields by two different processes involving the Pd-catalyzed annulation of arynes. Both processes appear to involve the catalytic, stepwise coupling of two very reactive substrates, an aryne and an organopalladium species, to generate excellent yields of cross-coupled products.

Zhijian Liu

2006-12-12

96

Problem Types in Synthetic Organic Chemistry Research: Implications for the Development of Curricular Problems for Second-Year Level Organic Chemistry Instruction  

ERIC Educational Resources Information Center

Understanding of the nature of science is key to the development of new curricular materials that mirror the practice of science. Three problem types (project level, synthetic planning, and day-to-day) in synthetic organic chemistry emerged during a thematic content analysis of the research experiences of eight practising synthetic organic

Raker, Jeffrey R.; Towns, Marcy H.

2012-01-01

97

Atmospheric Prebiotic Chemistry and Organic Hazes.  

PubMed

Earth's atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of prebiotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer - if formed - would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere. PMID:24143126

Trainer, Melissa G

2013-08-01

98

Atmospheric Prebiotic Chemistry and Organic Hazes  

PubMed Central

Earth’s atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of prebiotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer – if formed – would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere. PMID:24143126

Trainer, Melissa G.

2013-01-01

99

Atmospheric Prebiotic Chemistry and Organic Hazes  

NASA Technical Reports Server (NTRS)

Earth's atmospheric composition at the time of the origin of life is not known, but it has often been suggested that chemical transformation of reactive species in the atmosphere was a significant source of pre biotic organic molecules. Experimental and theoretical studies over the past half century have shown that atmospheric synthesis can yield molecules such as amino acids and nucleobases, but these processes are very sensitive to gas composition and energy source. Abiotic synthesis of organic molecules is more productive in reduced atmospheres, yet the primitive Earth may not have been as reducing as earlier workers assumed, and recent research has reflected this shift in thinking. This work provides a survey of the range of chemical products that can be produced given a set of atmospheric conditions, with a particular focus on recent reports. Intertwined with the discussion of atmospheric synthesis is the consideration of an organic haze layer, which has been suggested as a possible ultraviolet shield on the anoxic early Earth. Since such a haze layer - if formed - would serve as a reservoir for organic molecules, the chemical composition of the aerosol should be closely examined. The results highlighted here show that a variety of products can be formed in mildly reducing or even neutral atmospheres, demonstrating that contributions of atmospheric synthesis to the organic inventory on early Earth should not be discounted. This review intends to bridge current knowledge of the range of possible atmospheric conditions in the prebiotic environment and pathways for synthesis under such conditions by examining the possible products of organic chemistry in the early atmosphere.

Trainer, Melissa G.

2012-01-01

100

Integrating Advanced High School Chemistry Research with Organic Chemistry and Instrumental Methods of Analysis  

ERIC Educational Resources Information Center

This paper describes and discusses the unique chemistry course opportunities beyond the advanced placement-level available at a science and technology magnet high school. Students may select entry-level courses such as honors and advanced placement chemistry; they may also take electives in organic chemistry with instrumental methods of analysis;…

Kennedy, Brian J.

2008-01-01

101

Distributed Pore Chemistry in Porous Organic Polymers  

NASA Technical Reports Server (NTRS)

A method for making a biocompatible polymer article using a uniform atomic oxygen treatment is disclosed. The sub-strate may be subsequently optionally grated with a compatibilizing compound. Compatibilizing compounds may include proteins, phosphorylcholine groups, platelet adhesion preventing polymers, albumin adhesion promoters, and the like. The compatibilized substrate may also have a living cell layer adhered thereto. The atomic oxygen is preferably produced by a flowing afterglow microwave discharge, wherein the substrate resides in a sidearm out of the plasma. Also, methods for culturing cells for various purposes using the various membranes are disclosed as well. Also disclosed are porous organic polymers having a distributed pore chemistry (DPC) comprising hydrophilic and hydrophobic region, and a method for making the DPC by exposing the polymer to atomic oxygen wherein the rate of hydrophilization is greater than the rate of mass loss.

Koontz, Steven L. (Inventor)

1998-01-01

102

Atmospheric Chemistry Experiment (ACE) Measurements of Tropospheric and Stratospheric Chemistry and Long-Term Trends  

NASA Technical Reports Server (NTRS)

We highlight chemistry and trend measurement results from the Atmospheric Chemistry Experiment (ACE) which is providing precise middle troposphere to the lower thermosphere measurements with a 0.02/cm resolution Fourier transform spectrometer covering 750-4400/cm

Rinsland, Curtis P.; Bernath, Peter; Boone, Chris; Nassar, Ray

2007-01-01

103

Organic chemistry. Nanomole-scale high-throughput chemistry for the synthesis of complex molecules.  

PubMed

At the forefront of new synthetic endeavors, such as drug discovery or natural product synthesis, large quantities of material are rarely available and timelines are tight. A miniaturized automation platform enabling high-throughput experimentation for synthetic route scouting to identify conditions for preparative reaction scale-up would be a transformative advance. Because automated, miniaturized chemistry is difficult to carry out in the presence of solids or volatile organic solvents, most of the synthetic "toolkit" cannot be readily miniaturized. Using palladium-catalyzed cross-coupling reactions as a test case, we developed automation-friendly reactions to run in dimethyl sulfoxide at room temperature. This advance enabled us to couple the robotics used in biotechnology with emerging mass spectrometry-based high-throughput analysis techniques. More than 1500 chemistry experiments were carried out in less than a day, using as little as 0.02 milligrams of material per reaction. PMID:25554781

Buitrago Santanilla, Alexander; Regalado, Erik L; Pereira, Tony; Shevlin, Michael; Bateman, Kevin; Campeau, Louis-Charles; Schneeweis, Jonathan; Berritt, Simon; Shi, Zhi-Cai; Nantermet, Philippe; Liu, Yong; Helmy, Roy; Welch, Christopher J; Vachal, Petr; Davies, Ian W; Cernak, Tim; Dreher, Spencer D

2015-01-01

104

Form and Function: An Organic Chemistry Module.  

ERIC Educational Resources Information Center

This book is one in the series of Interdisciplinary Approaches to Chemistry (IAC) designed to help students discover that chemistry is a lively science and actively used to pursue solutions to the important problems of today. It is expected for students to see how chemistry takes place continuously all around and to readily understand the daily…

Jarvis, Bruce; Mazzocchi, Paul

105

Our Organic World Pre-AP Chemistry-Project  

E-print Network

Our Organic World Pre-AP Chemistry-Project Purpose: To study specific areas of organic chemistry research and group planning, the team will provide a lesson and visual that will teach the concept. A LEARNING BOX will be made to teach the lesson to a feeder school elementary class. All items

106

Teaching Introductory Organic Chemistry: 'Blooming' beyond a Simple Taxonomy.  

ERIC Educational Resources Information Center

Suggests that most students approach organic chemistry classes with a certain amount of apprehension and try to just manage or memorize the material rather than understand it. Recommends the use of Bloom's taxonomy as a way to increase comprehension and gives an example of how to use it in an organic chemistry classroom. (SOE)

Pungente, Michael D.; Badger, Rodney A.

2003-01-01

107

Evaluation of Interactive Technologies for Chemistry Websites: Educational Materials for Organic Chemistry Web Site (EMOC)  

Microsoft Academic Search

The Educational Materials for Organic Chemistry Project (EMOC) developed Web-based learning materials, which were accessible by students enrolled in a variety of undergraduate organic chemistry courses at a major midwestern university. EMOC was developed and implemented by the third author and had three distinct goals: (a) to develop interactive learning materials, (b) to develop interactive tools for this learning, and

Abby L. Parrill; Mary B. Nakhleh; William J. Donovan

2000-01-01

108

Greener Approaches to Undergraduate Chemistry Experiments.  

ERIC Educational Resources Information Center

This laboratory manual introduces the idea of Green Chemistry, which is the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances. Instructional samples are included to help teachers integrate green chemistry into the college chemistry curriculum. Each laboratory includes: (1) a…

Kirchhoff, Mary, Ed.; Ryan, Mary Ann, Ed.

109

An Undergraduate Organic Chemistry Laboratory: The Facile Hydrogenation of Methyl Trans-Cinnamate  

ERIC Educational Resources Information Center

Hydrogenation of alkenes is an important reaction in the synthesis of organic molecules. In this experiment, students conduct a high-yield microscale hydrogenation reaction of methyl "trans"-cinnamate using a readily available, safe, and convenient hydrogen source. The conditions are similar to those seen in an organic chemistry textbook for an…

O'Connor, Kenneth J.; Zuspan, Kimberly; Berry, Lonnie

2011-01-01

110

A One-Pot, Asymmetric Robinson Annulation in the Organic Chemistry Majors Laboratory  

ERIC Educational Resources Information Center

The Robinson annulation is a topic of importance in the second-year organic curriculum. A one-pot, enantioselective Robinson annulation is described. The experiment is completed in two lab periods and is geared towards the second-year organic chemistry major. To our knowledge, this is the first example of a one-pot enantioselective Robinson…

Lazarski, Kiel E.; Rich, Alan A.; Mascarenhas, Cheryl M.

2008-01-01

111

UNIVERSITY OF OREGON Organic Chemistry Faculty Position. The Department of Chemistry & Biochemistry invites applications for a tenure  

E-print Network

UNIVERSITY OF OREGON Organic Chemistry Faculty Position. The Department of Chemistry & Biochemistry invites applications for a tenure track or tenured position in organic chemistry beginning Fall 2014 at the rank of assistant or associate professor. Applicants in chemical biology, organic materials, organic

Oregon, University of

112

Organic First: A Biology-Friendly Chemistry Curriculum  

ERIC Educational Resources Information Center

In this essay, the author describes to biologists the advantages of organic-first curriculum, on the assumption that few biologists are regular readers of "Journal of Chemistry Education" and therefore are probably unaware of the method for integrating chemistry and biology curricula. The author begins with the assumption that the majority of…

Reingold, I. David

2005-01-01

113

Teaching Lab Report Writing through Inquiry: A Green Chemistry Stoichiometry Experiment for General Chemistry  

ERIC Educational Resources Information Center

We present an alternative to a traditional first-year chemistry laboratory experiment. This experiment has four key features: students utilize stoichiometry, learn and apply principles of green chemistry, engage in authentic scientific inquiry, and discover why each part of a scientific lab report is necessary. The importance and essential…

Cacciatore, Kristen L.; Sevian, Hannah

2006-01-01

114

Chem 341 Jasperse Syllabus 1 ORGANIC CHEMISTRY I: CHEMISTRY 341 SYLLABUS  

E-print Network

Chem 341 Jasperse Syllabus 1 ORGANIC CHEMISTRY I: CHEMISTRY 341 SYLLABUS Summer 2013 Dr. Craig P (see later page in syllabus for details.) These problems will be computer-graded, will give you some sheet each day! #12;Chem 341 Jasperse Syllabus 2 Final Exam: The last test will not be cumulative

Jasperse, Craig P.

115

A Template-Controlled Solid-State Reaction for the Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

An experiment for the organic chemistry laboratory that involves a template-controlled solid-state reaction is described. The experiment utilizes a template to direct the assembly of an olefin in the solid state that undergoes a [2 + 2] photodimerization.

Friscic, Tomislav; Hamilton, Tamara D.; Papaefstathiou, Giannis S.; MacGillivray, Leonard R.

2005-01-01

116

A Perspective on Physical Organic Chemistry  

PubMed Central

A perspective on the development of mechanistic carbene chemistry is presented. The author will point out questions that have been answered, and a next generation of questions will be proposed. PMID:24571434

2015-01-01

117

Integrating Pharmacology into the Organic Chemistry Course  

NSDL National Science Digital Library

Many nonchemistry majors are unaware of the unity between chemistry and biology and tend to separate the two disciplines conceptually. In a course designed to emphasize health-related issues using a pharmacological approach, students gained a much better

Colleen Kelley

2001-05-01

118

Quantum Dots: An Experiment for Physical or Materials Chemistry  

ERIC Educational Resources Information Center

An experiment is conducted for obtaining quantum dots for physical or materials chemistry. This experiment serves to both reinforce the basic concept of quantum confinement and providing a useful bridge between the molecular and solid-state world.

Winkler, L. D.; Arceo, J. F.; Hughes, W. C.; DeGraff, B. A.; Augustine, B. H.

2005-01-01

119

Contextualized Chemistry Education: The American experience  

Microsoft Academic Search

This paper is a survey of context?based chemistry education in the United States. It begins with a very brief overview of twentieth?century chemistry texts and teaching methods, followed by a short description of a pioneering secondary school text. The major emphasis is on post?secondary instruction and the central case study is provided by Chemistry in Context, a university text intended

A. Truman Schwartz

2006-01-01

120

Laboratory studies into the cosmic origins of organic chemistry  

NASA Astrophysics Data System (ADS)

We have constructed a novel merged-beams apparatus to study the cosmic origins of organic chemistry. Here we report rate coefficients measurements for reactions of atomic C with H+3. These data are important for astrochemical models.

de Ruette, N.; Miller, K. A.; O'Connor, A. P.; Stützel, J.; Urbain, X.; Savin, D. W.

2014-04-01

121

The Application of Physical Organic Chemistry to Biochemical Problems.  

ERIC Educational Resources Information Center

Presents the synthesis of the science of enzymology from application of the concepts of physical organic chemistry from a historical perspective. Summarizes enzyme and coenzyme mechanisms elucidated prior to 1963. (JM)

Westheimer, Frank

1986-01-01

122

Topic Sequence and Emphasis Variability of Selected Organic Chemistry Textbooks  

ERIC Educational Resources Information Center

Textbook choice has a significant effect upon course success. Among the factors that influence this decision, two of the most important are material organization and emphasis. This paper examines the sequencing of 19 organic chemistry topics, 21 concepts and skills, and 7 biological topics within nine of the currently available organic textbooks.…

Houseknecht, Justin B.

2010-01-01

123

Automated Combinatorial Chemistry in the Organic Chemistry Majors Laboratory  

ERIC Educational Resources Information Center

A multidisciplinary experiment has been developed in which students each synthesize a combinatorial library of 48 hydrazones with the aid of a liquid-handling robot. Each product is then subjected to a Kirby-Bauer disk diffusion assay to assess its antibacterial activity. Students gain experience working with automation and at the…

Nichols, Christopher J.; Hanne, Larry F.

2010-01-01

124

Academia-industry symbiosis in organic chemistry.  

PubMed

Collaboration between academia and industry is a growing phenomenon within the chemistry community. These sectors have long held strong ties since academia traditionally trains the future scientists of the corporate world, but the recent drastic decrease of public funding is motivating the academic world to seek more private grants. This concept of industrial "sponsoring" is not new, and in the past, some companies granted substantial amounts of money per annum to various academic institutions in exchange for prime access to all their scientific discoveries and inventions. However, academic and industrial interests were not always aligned, and therefore the investment has become increasingly difficult to justify from industry's point of view. With fluctuating macroeconomic factors, this type of unrestricted grant has become more rare and has been largely replaced by smaller and more focused partnerships. In our view, forging a partnership with industry can be a golden opportunity for both parties and can represent a true symbiosis. This type of project-specific collaboration is engendered by industry's desire to access very specific academic expertise that is required for the development of new technologies at the forefront of science. Since financial pressures do not allow companies to spend the time to acquire this expertise and even less to explore fundamental research, partnering with an academic laboratory whose research is related to the problem gives them a viable alternative. From an academic standpoint, it represents the perfect occasion to apply "pure science" research concepts to solve problems that benefit humanity. Moreover, it offers a unique opportunity for students to face challenges from the "real world" at an early stage of their career. Although not every problem in industry can be solved by research developments in academia, we argue that there is significant scientific overlap between these two seemingly disparate groups, thereby presenting an opportunity for a symbiosis. This type of partnership is challenging but can be a win-win situation if both parties agree on some general guidelines, including clearly defined goals and deliverables, biweekly meetings to track research progress, and quarterly or annual meetings to recognize overarching, common objectives. This Account summarizes our personal experience concerning collaborations with various industrial groups and the way it impacted the research programs for both sides in a symbiotic fashion. PMID:25702529

Michaudel, Quentin; Ishihara, Yoshihiro; Baran, Phil S

2015-03-17

125

Generation, Isolation, and Characterization of a Stable Enol from Grignard Addition to a Bis-Ester: A Microscale Experiment for the Undergraduate Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

An experiment is described that introduces students to the concept of temperature-dependent stability of the tetrahedral intermediate in an acyl-transfer reaction. The process involves the determination of the structure of an alpha-ketoester and its corresponding remarkably stable enol ester to suggest a mechanism for the formation of the products.

Nicaise, Olivier J. C.; Ostrom, Kyle F.; Dalke, Brent J.

2005-01-01

126

Tautomerization of Acetylacetone Enol. A Physical Organic Experiment in Kinetics and Thermodynamics.  

ERIC Educational Resources Information Center

Describes a physical organic experiment in thermodynamics and kinetics for undergraduate courses in organic chemistry, biochemistry, or physical chemistry. Details background information, solution preparations, equipment and methods, and the suggested experiments such as determination of general-base-catalytic coefficients and the Bronsted…

Spyridis, Greg T.; Meany, J. E.

1988-01-01

127

Positive Impacts Using POGIL in Organic Chemistry  

ERIC Educational Resources Information Center

A student-centered learning technique, process-oriented, guided-inquiry learning (POGIL), has been developed as a pedagogical technique that facilitates collaborative and cooperative learning in the chemistry classroom. With the use of this technique, students enhance their higher-order thinking skills and process skills synergistically. In…

Hein, Sara M.

2012-01-01

128

Infusing the Chemistry Curriculum with Green Chemistry Using Real-World Examples, Web Modules, and Atom Economy in Organic Chemistry Courses  

NASA Astrophysics Data System (ADS)

Green chemistry principles and practices have been infused in the chemistry curriculum at the University of Scranton, including courses in general, organic, and inorganic chemistry, biochemistry, environmental, polymer, industrial, and advanced organic chemistry, and chemical toxicology. Web-based green chemistry teaching modules have been developed for each of these courses. We describe the principles underlying green chemistry and methods of introducing these concepts into the curriculum with an example of incorporating green chemistry into the undergraduate lecture and laboratory organic sequence. See Featured Molecules .

Cann, Michael C.; Dickneider, Trudy A.

2004-07-01

129

Hydrogen chemistry - Perspective on experiment and theory. [atmospheric chemistry  

NASA Technical Reports Server (NTRS)

A review is presented of the advantages and limitations of various experimental methods for the investigation of the kinetics of hydrogen chemistry, including classic thermal and photochemical methods and the crossed molecular beam method. Special attention is given to the flash photolysis-resonance fluorescence apparatus developed by Braun et al, in which repetitive vacuum UV flashes result in the photolytic generation of the desired species, and to the discharge-flow technique. The use of various theoretical methods for the selection or elimination of kinetic data is considered in a brief discussion of the rate theory of two-body encounters and recombination-dissociation processes in neutral reactions. Recent kinetic studies of a series of OH reactions and of a major loss process for odd H in the stratosphere are summarized.

Kaufman, F.

1975-01-01

130

Synthesis of Ethyl Nalidixate: A Medicinal Chemistry Experiment  

ERIC Educational Resources Information Center

A series of laboratory experiments that complement a medicinal chemistry lecture course in drug design and development have been developed. The synthesis of ethyl nalidixate covers three separate experimental procedures, all of which can be completed in three, standard three-hour lab classes and incorporate aspects of green chemistry such as…

Leslie, Ray; Leeb, Elaine; Smith, Robert B.

2012-01-01

131

An Efficient Statistical Approach for Automatic Organic Chemistry Summarization  

Microsoft Academic Search

In this paper, we propose an efficient strategy for summarizing scientific documents in Organic Chemistry that concentrates\\u000a on numerical treatments. We present its implementation named yachs (Yet Another Chemistry Summarizer) that combines a specific document pre-processing with a sentence scoring method relying\\u000a on the statistical properties of documents. We show that yachs achieves the best results among several other summarizers

Florian Boudin; Juan Manuel Torres Moreno; Patricia Velázquez-morales

2008-01-01

132

Development of chemistry attitudes and experiences questionnaire (CAEQ)  

NASA Astrophysics Data System (ADS)

In this article we describe the development of the Chemistry Attitudes and Experiences Questionnaire (CAEQ) that measures first-year university chemistry students' attitude toward chemistry, chemistry self-efficacy, and learning experiences. The instrument was developed as part of a larger study and sought to fulfill a need for an instrument to investigate factors that influence student enrollment choice. We set out to design the instrument in a manner that would maximize construct validity. The CAEQ was piloted with a cohort of science and technology students (n = 129) at the end of their first year. Based on statistical analysis the instrument was modified and subsequently administered on two occasions at two tertiary institutions (n = 669). Statistical data along with additional data gathered from interviews suggest that the CAEQ possesses good construct validity and will prove a useful tool for tertiary level educators who wish to gain an understanding of factors that influence student choice of chemistry enrolment.

Dalgety, Jacinta; Coll, Richard K.; Jones, Alister

2003-09-01

133

A Green, Guided-Inquiry Based Electrophilic Aromatic Substitution for the Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

We developed an alternative electrophilic aromatic substitution reaction for the organic chemistry teaching laboratory. The experiment is an electrophilic iodination reaction of salicylamide, a popular analgesic, using environmentally friendly reagents--sodium iodide and household bleach. Further, we designed the lab as a guided-inquiry…

Eby, Eric; Deal, S. Todd

2008-01-01

134

Borohydride Reduction of Estrone: Demonstration of Diastereoselectivity in the Undergraduate Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

This experiment presents a guided-inquiry approach to the demonstration of diastereoselectivity in an undergraduate organic chemistry laboratory. Chiral hindered ketones such as estrone, undergo facile reduction with sodium borohydride in a highly diastereoselective manner. The diastereomeric estradiols produced in the reaction can be analyzed and…

Aditya, Animesh; Nichols, David E.; Loudon, G. Marc

2008-01-01

135

Interdisciplinary Learning for Chemical Engineering Students from Organic Chemistry Synthesis Lab to Reactor Design to Separation  

ERIC Educational Resources Information Center

A novel approach to the Chemical Engineering curriculum sequence of courses at West Point enabled our students to experience a much more realistic design process, which more closely replicated a real world scenario. Students conduct the synthesis in the organic chemistry lab, then conduct computer modeling of the reaction with ChemCad and…

Armstrong, Matt; Comitz, Richard L.; Biaglow, Andrew; Lachance, Russ; Sloop, Joseph

2008-01-01

136

A Practical Introduction to Separation and Purification Techniques for the Beginning Organic Chemistry Laboratory.  

ERIC Educational Resources Information Center

Describes a sequence of experiments developed at Texas A&M University for use in one-semester and two-semester (nonmajors) organic chemistry courses to teach a maximum number of separation and purification techniques such as distillations, recrystallization, liquid-liquid extraction, and chromatography. (SK)

Leonard, Jack E.

1981-01-01

137

Structure Determination of Unknown Organic Liquids Using NMR and IR Spectroscopy: A General Chemistry Laboratory  

ERIC Educational Resources Information Center

This experiment introduced general chemistry students to the basic concepts of organic structures and to the power of spectroscopic methods for structure determination. Students employed a combination of IR and NMR spectroscopy to perform de novo structure determination of unknown alcohols, without being provided with a list of possible…

Pavel, John T.; Hyde, Erin C.; Bruch, Martha D.

2012-01-01

138

A Guided Inquiry Liquid/Liquid Extractions Laboratory for Introductory Organic Chemistry  

ERIC Educational Resources Information Center

A guided inquiry laboratory experiment for teaching liquid/liquid extractions to first semester undergraduate organic chemistry students is described. This laboratory is particularly useful for introductory students as the analytes that are separated are highly colored dye molecules. This allows students to track into which phase each analyte…

Raydo, Margaret L.; Church, Megan S.; Taylor, Zane W.; Taylor, Christopher E.; Danowitz, Amy M.

2015-01-01

139

Remote-controlled experiments with cloud chemistry  

NASA Astrophysics Data System (ADS)

Developing cleaner chemical processes often involves sophisticated flow-chemistry equipment that is not available in many economically developing countries. For reactions where it is the data that are important rather than the physical product, the networking of chemists across the internet to allow remote experimentation offers a viable solution to this problem.

Skilton, Ryan A.; Bourne, Richard A.; Amara, Zacharias; Horvath, Raphael; Jin, Jing; Scully, Michael J.; Streng, Emilia; Tang, Samantha L. Y.; Summers, Peter A.; Wang, Jiawei; Pérez, Eduardo; Asfaw, Nigist; Aydos, Guilherme L. P.; Dupont, Jairton; Comak, Gurbuz; George, Michael W.; Poliakoff, Martyn

2015-01-01

140

CODEX: Assessing the Historical Context of Chemistry and Organics on Mars  

NASA Astrophysics Data System (ADS)

The Chemistry, Organics and Dating EXperiment (CODEX) is a laser desorption time-of-flight mass spectrometer designed for use on Mars, which, by varying the type of ionization used, can operate as an elemental detector, an organics detector, and a radiometric dating instrument. CODEX uses three ionization modes: A) laser ablation mass spectrometry (LAMS) to measure chemistry and isotopes, B) two-step laser desorption/ionization mass spectrometry (L2MS) to measure organics, and C) laser desorption resonance ionization mass spectrometry (LDRIMS) to measure rubidium-strontium geochronology. Using these modes sequentially, CODEX interrogates hundreds of locations on the surface of a drill core, each of which are initially cleaned by laser ablation to remove surface contaminants. Using microscopic mapping, CODEX places elemental chemistry observations in spatial and temporal context with organic signatures revealing the complex historical context of chemistry and organics. The modes of CODEX have been demonstrated on three well-known samples: a) the Boulder Creek Granite (chemistry and dating), b) the carbonaceous chondrite Murchison (organics and chemistry), and c) the Martian meteorite Zagami (dating). The BCG measurements result in a high-sensitivity chemistry measurements, with isotope ratio precision exceeding ±0.35%; using dating mode, we derived an average age of 1727±62 Ma, as compared to a TIMS age of 1700±40 Ma. The measurements of the Murchison meteorite revealed hundreds of organic compounds consistent with an abiotic carbonaceous chondrite, and elemental abundances that match previous work. Finally, Zagami is a Martian meteorite with a Rb-Sr age of 166±6 Ma. Our measurements result in an age of 170±105 Ma, consistent with the previously published dates, and an accuracy exceeding NASA requirements (±200 Ma).

Anderson, F. Scott; Whitaker, Tom; Levine, Jonathan

2014-05-01

141

Organic chemistry on Titan: Surface interactions  

Microsoft Academic Search

The interaction of Titan's organic sediments with the surface (solubility in nonpolar fluids) is discussed. How Titan's sediments can be exposed to an aqueous medium for short, but perhaps significant, periods of time is also discussed. Interactions with hydrocarbons and with volcanic magmas are considered. The alteration of Titan's organic sediments over geologic time by the impacts of meteorites and

W. Reid Thompson; Carl Sagan

1992-01-01

142

Experiments in Chemistry: A Model Science Software Tool.  

ERIC Educational Resources Information Center

Describes "Experiments in Chemistry," in which experiments are performed using software and hardware interfaced to the Apple microcomputer's game paddle port. Experiments include temperature, pH electrode, and EMF (cell potential determinations, oxidation-reduction titrations, and precipitation titrations) investigations. (JN)

Malone, Diana; Tinker, Robert

1984-01-01

143

The Organic Chemistry of Conducting Polymers  

SciTech Connect

For the last several years, we have examined the fundamental principles of conduction in one-dimensional systems, i.e., molecular “wires”. It is, of course, widely recognized that such systems, as components of electronically conductive materials, function in a two- and three-dimensional milieu. Thus interchain hopping and grain-boundary resistivity are limiting conductivity factors in highly conductive materials, and overall conductivity is a function of through-chain and boundary hopping. We have given considerable attention to the basic principles underlying charge transport (the “rules of the game”) in two-dimensional systems by using model systems which allow direct observation of such processes, including the examination of tunneling and hopping as components of charge transfer. In related work, we have spent considerable effort on the chemistry of conjugated heteropolymers, most especially polythiophens, with the aim of using these most efficient of readily available electroactive polymers in photovoltaic devices.

Tolbert, Laren Malcolm [Georgia Institute of Technology

2014-12-01

144

A Research Module for the Organic Chemistry Laboratory: Multistep Synthesis of a Fluorous Dye Molecule  

PubMed Central

A multi-session research-like module has been developed for use in the undergraduate organic teaching laboratory curriculum. Students are tasked with planning and executing the synthesis of a novel fluorous dye molecule and using it to explore a fluorous affinity chromatography separation technique, which is the first implementation of this technique in a teaching laboratory. Key elements of the project include gradually introducing students to the use of the chemical literature to facilitate their searching, as well as deliberate constraints designed to force them to think critically about reaction design and optimization in organic chemistry. The project also introduces students to some advanced laboratory practices such as Schlenk techniques, degassing of reaction mixtures, affinity chromatography, and microwave-assisted chemistry. This provides students a teaching laboratory experience that closely mirrors authentic synthetic organic chemistry practice in laboratories throughout the world. PMID:24501431

2014-01-01

145

Solventless and One-Pot Synthesis of Cu(II) Phthalocyanine Complex: A Green Chemistry Experiment  

ERIC Educational Resources Information Center

With the growing awareness of green chemistry, it is increasingly important for students to understand this concept in the context of laboratory experiments. Although microwave-assisted organic synthesis has become a common and invaluable technique in recent years, there have been few procedures published for microwave-assisted inorganic synthesis…

Sharma, R. K.; Sharma, Chetna; Sidhwani, Indu Tucker

2011-01-01

146

A Statistical Evaluation: Peer-led Team Learning in an Organic Chemistry Course.  

ERIC Educational Resources Information Center

Reports the status of peer-led learning, also known as Workshop Chemistry. This National Science Foundation (NSF) systemic-reform initiative focuses on general chemistry, organic chemistry, and biochemistry. (DDR)

Lyle, Kenneth S.; Robinson, William R.

2003-01-01

147

Oxidation and Reduction Reactions in Organic Chemistry  

ERIC Educational Resources Information Center

A variety of approaches to the concept of oxidation and reduction appear in organic textbooks. The method proposed here is different than most published approaches. The oxidation state is calculated by totaling the number of heterogeneous atoms, [pi]-bonds, and rings. A comparison of the oxidation states of reactant and product determine what type…

Shibley, Ivan A., Jr.; Amaral, Katie E.; Aurentz, David J.; McCaully, Ronald J.

2010-01-01

148

Carbohydrates as synthetic tools in organic chemistry.  

PubMed

While amino acids, terpenes and alkaloids have found broad application as tools in stereoselective organic synthesis, carbohydrates have only lately been recognised as versatile starting materials for chiral auxiliaries, reagents, ligands and organocatalysts. The structural diversity of carbohydrates and the high density of functional groups offer a wide variety of opportunities for derivatization and tailoring of synthetic tools to a specific problem. PMID:17712826

Boysen, Mike M K

2007-01-01

149

Omar Yaghi on Chemistry and Metal Organic Frameworks  

ScienceCinema

In this edited version of the hour long talk, Omar Yaghi, director of the Molecular Foundry, sat down in conversation with Jeff Miller, head of Public Affairs, on July 11th, 2012 to discuss his fascination with the hidden world of chemistry and his work on Metal Organic Frameworks.

Omar Yaghi

2013-06-24

150

Telling It like It Is: Teaching Mechanisms in Organic Chemistry  

ERIC Educational Resources Information Center

In this article I support and extend the ideas presented by J. Brent Friesen in his article "Saying What You Mean; Teaching Mechanisms in Organic Chemistry" ("JCE" November, 2008). I emphasize "telling the truth" about proton transfers. The truth is that in aqueous acid most reactions are subject to "specific" acid catalysis: the only kinetically…

Ault, Addison

2010-01-01

151

Sudoku Puzzles for First-Year Organic Chemistry Students  

ERIC Educational Resources Information Center

Sudoku puzzle was designed to teach about amino acids and functional groups to the students of undergraduate organic chemistry students. The puzzles focus on helping the student learn the name, 3-letter code and 1-letter code of common amino acids and functional groups.

Perez, Alice L.; Lamoureux, G.

2007-01-01

152

TECHNETIUM CHEMISTRY IN HLW: ROLE OF ORGANIC COMPLEXANTS  

EPA Science Inventory

Technetium complexation with organic compounds in tank waste plays a significant role in the redox chemistry of Tc and the partitioning of Tc between the supernatant and sludge components in waste tanks. These processes need to be understood so that strategies to effectively remo...

153

Lesson Planner for Demonstrations in Organic Chemistry Videodisc  

Microsoft Academic Search

Lesson Planner is a Microsoft Excel (1) macro that generates barcodes for video included on the Demonstrations in Organic Chemistry videodisc (2). It allows instructors who do not have computer control capability for their videodisc player, but do have a barcode reader, to prepare customized lessons for use in the classroom or laboratory. There is no need to flip through

Todd A. Surovell

1995-01-01

154

The Role of Spatial Ability and Achievement in Organic Chemistry.  

ERIC Educational Resources Information Center

This study investigated the role that spatial ability has in achievement in organic chemistry. Spatial ability was defined as containing two subfactors--spatial visualization and spatial orientation. Spatial visualization is the ability to mentally manipulate pictorially presented stimuli; involved in the processes of manipulation are the…

Pribyl, Jeffrey R.; Bodner, George M.

155

Patterns in Organometallic Chemistry with Application in Organic Synthesis.  

ERIC Educational Resources Information Center

Of interest in this discussion of organometallic complexes are stoichiometric or catalytic reagents for organic synthesis in the complex transformations observed during synthesis for transition metal organometallic complexes. Detailed are general reaction types from which the chemistry or many transition metal organometallic complexes can be…

Schwartz, Jeffrey; Labinger, Jay A.

1980-01-01

156

Toward Consistent Terminology for Cyclohexane Conformers in Introductory Organic Chemistry  

ERIC Educational Resources Information Center

Recommended changes in use of cyclohexane conformers and their nomenclature will remedy inconsistencies in cyclohexane conformers and their nomenclature that exist across currently used organic chemistry textbooks. These inconsistencies prompted this logical analysis and the resulting recommendations. Recommended conformer names are "chair",…

Nelson, Donna J.; Brammer, Christopher N.

2011-01-01

157

Non-Mathematical Problem Solving in Organic Chemistry  

ERIC Educational Resources Information Center

Differences in problem-solving ability among organic chemistry graduate students and faculty were studied within the domain of problems that involved the determination of the structure of a molecule from the molecular formula of the compound and a combination of IR and [to the first power]H NMR spectra. The participants' performance on these tasks…

Cartrette, David P.; Bodner, George M.

2010-01-01

158

Spectroelectrochemical Sensing of Aqueous Iron: An Experiment for Analytical Chemistry  

ERIC Educational Resources Information Center

We have designed a laboratory experiment to illustrate the use of spectroelectrochemical techniques for determination of aqueous iron. The experiment described in this article is applicable to an undergraduate laboratory course in analytical chemistry. Students are asked to fabricate spectroelectrochemical sensors, make electrochemical and optical…

Shtoyko, Tanya; Stuart, Dean; Gray, H. Neil

2007-01-01

159

Academia–Industry Symbiosis in Organic Chemistry  

PubMed Central

CONSPECTUS Collaboration between academia and industry is a growing phenomenon within the chemistry community. These sectors have long held strong ties since academia traditionally trains the future scientists of the corporate world, but the recent drastic decrease of public funding is motivating the academic world to seek more private grants. This concept of industrial “sponsoring” is not new, and in the past, some companies granted substantial amounts of money per annum to various academic institutions in exchange for a prime access to all their scientific discoveries and inventions. However, academic and industrial interests were not always aligned, and therefore the investment has become increasingly difficult to justify from industry's point of view. With fluctuating macroeconomic factors, this type of unrestricted grant has become more rare and has been largely replaced by smaller and more focused partnerships. In our view, forging a partnership with industry can be a golden opportunity for both parties and can represent a true symbiosis. This type of project-specific collaboration is engendered by industry's desire to access very specific academic expertise that is required for the development of new technologies at the forefront of science. Since financial pressures do not allow companies to spend the time to acquire this expertise and even less to explore fundamental research, partnering with an academic laboratory whose research is related to the problem gives them a viable alternative. From an academic standpoint, it represents the perfect occasion to apply “pure science” research concepts to solve problems that benefit humanity. Moreover, it offers a unique opportunity for students to face challenges from the “real world” at an early stage of their career. Although not every problem in industry can be solved by research developments in academia, we argue that there is significant scientific overlap between these two seemingly disparate groups, thereby presenting an opportunity for a symbiosis. This type of partnership is challenging but can be a win-win situation if both parties agree on some general guidelines. PMID:25702529

Michaudel, Quentin; Ishihara, Yoshihiro; Baran, Phil S.

2015-01-01

160

Solvated Electrons in Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

A novel experiment is described in which solvated electrons in liquid ammonia reduce a benzyl alcohol carbon without affecting the aromatic ring. The reductive activity of solvated electrons can be partially or completely quenched through the addition of electron scavengers to the reaction mixture. The effectiveness of these scavengers was found…

Ilich, Predrag-Peter; McCormick, Kathleen R.; Atkins, Adam D.; Mell, Geoffrey J.; Flaherty, Timothy J.; Bruck, Martin J.; Goodrich, Heather A.; Hefel, Aaron L.; Juranic, Nenad; Seleem, Suzanne

2010-01-01

161

Chemistry Notes.  

ERIC Educational Resources Information Center

Describes 13 activities, experiments and demonstrations, including the preparation of iron (III) chloride, simple alpha-helix model, investigating camping gas, redox reactions of some organic compounds, a liquid crystal thermometer, and the oxidation number concept in organic chemistry. (JN)

School Science Review, 1981

1981-01-01

162

Cooperative Chemistry  

NSDL National Science Digital Library

Concept mapping in the organic chemistry laboratory can supplant cookbook activities with higher cognitive exercises. The common thread of most organic lab experiments is the synthesis, isolation, purification, and characterization of a carbon compound. T

Allan A. Gahr

2003-02-01

163

Planetary Organic Chemistry and the Origins of Biomolecules  

PubMed Central

Organic chemistry on a planetary scale is likely to have transformed carbon dioxide and reduced carbon species delivered to an accreting Earth. According to various models for the origin of life on Earth, biological molecules that jump-started Darwinian evolution arose via this planetary chemistry. The grandest of these models assumes that ribonucleic acid (RNA) arose prebiotically, together with components for compartments that held it and a primitive metabolism that nourished it. Unfortunately, it has been challenging to identify possible prebiotic chemistry that might have created RNA. Organic molecules, given energy, have a well-known propensity to form multiple products, sometimes referred to collectively as “tar” or “tholin.” These mixtures appear to be unsuited to support Darwinian processes, and certainly have never been observed to spontaneously yield a homochiral genetic polymer. To date, proposed solutions to this challenge either involve too much direct human intervention to satisfy many in the community, or generate molecules that are unreactive “dead ends” under standard conditions of temperature and pressure. Carbohydrates, organic species having carbon, hydrogen, and oxygen atoms in a ratio of 1:2:1 and an aldehyde or ketone group, conspicuously embody this challenge. They are components of RNA and their reactivity can support both interesting spontaneous chemistry as part of a “carbohydrate world,” but they also easily form mixtures, polymers and tars. We describe here the latest thoughts on how on this challenge, focusing on how it might be resolved using minerals containing borate, silicate, and molybdate, inter alia. PMID:20504964

Benner, Steven A.; Kim, Hyo-Joong; Kim, Myung-Jung; Ricardo, Alonso

2010-01-01

164

Solar Energy Experiment for Beginning Chemistry.  

ERIC Educational Resources Information Center

Describes an experiment illustrating how such chemical concepts as light absorption, thermodynamics, and solid-state photovoltaics can be incorporated into solar energy education. Completed in a three-hour period, the experiment requires about two hours for data collections with the remaining hour devoted to calculations and comparison of results.…

Davis, Clyde E.

1983-01-01

165

Some Experiments in Sulfur-Nitrogen Chemistry.  

ERIC Educational Resources Information Center

Briefly surveys the main structural types of sulfur-nitrogen compounds, and describes syntheses, suitable as undergraduate experiments, which illustrate four of the five types of cyclic species. Laboratory procedures, background information, and discussion of results for these experiments are provided. (Author/JN)

Banister, Arthur J.; Smith, Nigel R. M.

1982-01-01

166

A Process Model for the Comprehension of Organic Chemistry Notation  

NASA Astrophysics Data System (ADS)

This dissertation examines the cognitive processes individuals use when reading organic chemistry equations and factors that affect these processes, namely, visual complexity of chemical equations and participant characteristics (expertise, spatial ability, and working memory capacity). A six stage process model for the comprehension of organic chemistry notation was proposed that accounts for the movement of the eyes across the chemical equation (get next); the search of a chemical structure for key features (search); the encoding of features to create an internal representation (encoding and access lexicon); the assignments of relationships among features in the same molecule (intramolecular relationship) and between molecules (intermolecular relationship); and a check of the internal representation for inconsistencies (reaction wrap-up). Two studies were conducted in this investigation. The first study assessed the validity and ability of the Complexity Rubric for Organic Chemistry Notation to quantify visual complexity of structural formulas. A three-part investigation examined the content of the rubric, its capacity to measure visual complexity, and its ability to predict visual complexity as perceived by novices. The results suggest that the rubric differentiates structural formulas with high visual complexity from those with medium-low visual complexity. A follow-up study examined the effect of prior knowledge on the encoding of organic formulas and suggests that knowledge from domains outside chemistry plays a role in the perceived complexity of structural formulas. In the second study, eye tracking methodology was used to validate the proposed process model for the comprehension of organic chemistry notation and examine factors that affect these processes. Eight instructors and 19 students were eye tracked while reading five high/low complexity pairs of organic chemistry equations for comprehension. The frequency, duration, and sequence of participants' eye fixations were examined. The results provide evidence for each stage of the proposed process model and suggest that visual complexity of the equation, as measured by the rubric, significantly affects the viewing patterns of participants. Expertise of the participant was also shown to play a significant role in viewing patterns. The effects of working memory capacity and spatial ability were shown to be less consistent and may be topic dependent.

Havanki, Katherine L.

167

Infusing the Chemistry Curriculum with Green Chemistry Using Real-World Examples, Web Modules, and Atom Economy in Organic Chemistry Courses  

ERIC Educational Resources Information Center

Green chemistry is the awareness of the damaging environmental effects due to chemical research and inventions. There is emphasis on a need to include green chemistry in synthesis with atom economy in organic chemistry curriculum to ensure an environmentally conscious future generation of chemists, policy makers, health professionals and business…

Cann, Michael C.; Dickneider, Trudy A.

2004-01-01

168

Organic Chemistry Self Instructional Package 3: Alkanes-Homologous Series and Isomerism.  

ERIC Educational Resources Information Center

This booklet, one of a series of 17 developed at Prince George's Community College, Largo, Maryland, provides an individualized, self-paced undergraduate organic chemistry instruction module designed to augment any course in organic chemistry but particularly those taught using the text "Organic Chemistry" by Morrison and Boyd. The entire series…

Zdravkovich, V.

169

Organic Chemistry Self Instructional Package 7: Alkenes-Nomenclature and Isomerism.  

ERIC Educational Resources Information Center

This booklet, one of a series of 17 developed at Prince George's Community College, Largo, Maryland, provides an individualized, self-paced undergraduate organic chemistry instruction module designed to augment any course in organic chemistry but particularly those taught using the text "Organic Chemistry" by Morrison and Boyd. The entire series…

Zdravkovich, V.

170

Integration of Computational and Preparative Techniques to Demonstrate Physical Organic Concepts in Synthetic Organic Chemistry: An Example Using Diels-Alder Reaction  

ERIC Educational Resources Information Center

The Diels-Alder reaction is used as an example for showing the integration of computational and preparative techniques, which help in demonstrating the physical organic concepts in synthetic organic chemistry. These experiments show that the students should not accept the computational results without questioning them and in many Diels-Alder…

Palmer, David R. J.

2004-01-01

171

Organic Chemistry in the Saturn System: Titan and Enceladus  

E-print Network

Organic Chemistry in the Saturn System: Titan and Enceladus J. H. Waite J. Westlake B. Magee T­4 Saturn 1.7 (+0.75/­0.45) x 10­5 Jupiter 2.25±0.35 x 10­5 Protosolar 2.1±0.4 x 10­5 D/H Cometary Were parIally devolaIlized in the early Saturn nebula, losing CO, N2, and Ar, but not CH4 Mousis et al

Kaiser, Ralf I.

172

Ionic Liquids and Green Chemistry: A Lab Experiment  

ERIC Educational Resources Information Center

Although ionic liquids have been investigated as solvents for many applications and are starting to be used in industrial processes, only a few lab experiments are available to introduce students to these materials. Ionic liquids have been discussed in the context of green chemistry, but few investigations have actually assessed the degree of…

Stark, Annegret; Ott, Denise; Kralisch, Dana; Kreisel, Guenter; Ondruschka, Bernd

2010-01-01

173

UNESCO Chemistry Teaching Project in Asia: Experiments on Nuclear Science.  

ERIC Educational Resources Information Center

This teacher's guide on nuclear science is divided into two parts. The first part is a discussion of some of the concepts in nuclear chemistry including radioactivity, types of disintegration, radioactive decay and growth, and tracer techniques. The relevant experiments involving the use of radioisotopes are presented in the second part. The…

Dhabanandana, Salag

174

Tropospheric Chemistry of Internally Mixed Sea Salt and Organic Particles: Surprising Reactivity of NaCl with Weak Organic Acids  

SciTech Connect

Chemical imaging analysis of internally mixed sea salt/organic particles collected on board the Department of Energy (DOE) G-1 aircraft during the 2010 Carbonaceous Aerosols and Radiative Effects Study (CARES) was performed using electron microscopy and X-ray spectro-microscopy techniques. Substantial chloride depletion in aged sea salt particles was observed, which could not be explained by the known atmospheric reactivity of sea salt with inorganic nitric and sulfuric acids. We present field evidence that chloride components in sea salt particles may effectively react with organic acids releasing HCl gas to the atmosphere, leaving behind particles depleted in chloride and enriched in the corresponding organic salts. While formation of the organic salts products is not thermodynamically favored for bulk aqueous chemistry, these reactions in aerosol are driven by high volatility and irreversible evaporation of the HCl product from drying particles. These field observations were corroborated in a set of laboratory experiments where NaCl particles mixed with organic acids were found to be depleted in chloride. Combined together, the results indicate substantial chemical reactivity of sea salt particles with secondary organics that has been largely overlooked in the atmospheric aerosol chemistry. Atmospheric aging, and especially hydration-dehydration cycles of mixed sea salt/organic particles may result in formation of organic salts that will modify acidity, hygroscopic and optical properties of aged particles.

Laskin, Alexander; Moffet, Ryan C.; Gilles, Marry K.; Fast, Jerome D.; Zaveri, Rahul A.; Wang, Bingbing; Nigge, P.; Shutthanandan, Janani I.

2012-08-03

175

Integration of Video-Based Demonstrations to Prepare Students for the Organic Chemistry Laboratory  

NASA Astrophysics Data System (ADS)

Consistent, high-quality introductions to organic chemistry laboratory techniques effectively and efficiently support student learning in the organic chemistry laboratory. In this work, we developed and deployed a series of instructional videos to communicate core laboratory techniques and concepts. Using a quasi-experimental design, we tested the videos in five traditional laboratory experiments by integrating them with the standard pre-laboratory student preparation presentations and instructor demonstrations. We assessed the influence of the videos on student laboratory knowledge and performance, using sections of students who did not view the videos as the control. Our analysis of pre-quizzes revealed the control group had equivalent scores to the treatment group, while the post-quiz results show consistently greater learning gains for the treatment group. Additionally, the students who watched the videos as part of their pre-laboratory instruction completed their experiments in less time.

Nadelson, Louis S.; Scaggs, Jonathan; Sheffield, Colin; McDougal, Owen M.

2014-12-01

176

Spanish-Speaking English Language Learners' Experiences in High School Chemistry Education  

ERIC Educational Resources Information Center

This article reports on the experiences of Spanish-speaking English language learners in high school chemistry courses, focusing largely on experiences in learning the English language, experiences learning chemistry, and experiences learning chemistry in the English language. The findings illustrate the cognitive processes the students undertake…

Flores, Annette; Smith, K. Christopher

2013-01-01

177

New insights into Titan's organic chemistry in the gas and aerosol phases.  

PubMed

Titan, the largest satellite of Saturn, with a dense atmosphere very rich in organics, and many couplings in the various parts of its "geofluid", is a reference for studying prebiotic chemistry on a planetary scale. New data have been obtained from experiments simulating this organic chemistry (gas and aerosol phases), within the right ranges of temperature and a careful avoiding of any chemical contamination. They show a very good agreement with the observational data, demonstrating for the first time the formation of all the organic species already detected in Titan atmosphere including, at last, C4N2, together with many other species not yet detected in Titan. This strongly suggests the presence of more complex organics in Titan's atmosphere and surface, including high molecular weight polyynes and cyanopolyynes. The NASA-ESA Cassini-Huygens mission has been successfully launched in October 1997. The Cassini spacecraft will reach the Saturn system in 2004 and become an orbiter around Saturn, while the Huygens probe will penetrate into Titan's atmosphere. In situ measurements, in particular from Huygens GC-MS and ACP instruments, will provide a detailed analysis of the organics present in the air, aerosols, and surface. This very ambitious mission should yield much information of crucial importance for our knowledge of the complexity of Titan's chemistry, and, more generally for the field of exobiology. PMID:11543331

Raulin, F; Coll, P; Smith, N; Benilan, Y; Bruston, P; Gazeau, M C

1999-01-01

178

The chemistry of cyborgs--interfacing technical devices with organisms.  

PubMed

The term "cyborg" refers to a cybernetic organism, which characterizes the chimera of a living organism and a machine. Owing to the widespread application of intracorporeal medical devices, cyborgs are no longer exclusively a subject of science fiction novels, but technically they already exist in our society. In this review, we briefly summarize the development of modern prosthetics and the evolution of brain-machine interfaces, and discuss the latest technical developments of implantable devices, in particular, biocompatible integrated electronics and microfluidics used for communication and control of living organisms. Recent examples of animal cyborgs and their relevance to fundamental and applied biomedical research and bioethics in this novel and exciting field at the crossroads of chemistry, biomedicine, and the engineering sciences are presented. PMID:24288270

Giselbrecht, Stefan; Rapp, Bastian E; Niemeyer, Christof M

2013-12-23

179

Size distribution dynamics reveal particle-phase chemistry in organic aerosol formation  

PubMed Central

Organic aerosols are ubiquitous in the atmosphere and play a central role in climate, air quality, and public health. The aerosol size distribution is key in determining its optical properties and cloud condensation nucleus activity. The dominant portion of organic aerosol is formed through gas-phase oxidation of volatile organic compounds, so-called secondary organic aerosols (SOAs). Typical experimental measurements of SOA formation include total SOA mass and atomic oxygen-to-carbon ratio. These measurements, alone, are generally insufficient to reveal the extent to which condensed-phase reactions occur in conjunction with the multigeneration gas-phase photooxidation. Combining laboratory chamber experiments and kinetic gas-particle modeling for the dodecane SOA system, here we show that the presence of particle-phase chemistry is reflected in the evolution of the SOA size distribution as well as its mass concentration. Particle-phase reactions are predicted to occur mainly at the particle surface, and the reaction products contribute more than half of the SOA mass. Chamber photooxidation with a midexperiment aldehyde injection confirms that heterogeneous reaction of aldehydes with organic hydroperoxides forming peroxyhemiacetals can lead to a large increase in SOA mass. Although experiments need to be conducted with other SOA precursor hydrocarbons, current results demonstrate coupling between particle-phase chemistry and size distribution dynamics in the formation of SOAs, thereby opening up an avenue for analysis of the SOA formation process. PMID:23818634

Shiraiwa, Manabu; Yee, Lindsay D.; Schilling, Katherine A.; Loza, Christine L.; Craven, Jill S.; Zuend, Andreas; Ziemann, Paul J.; Seinfeld, John H.

2013-01-01

180

Size distribution dynamics reveal particle-phase chemistry in organic aerosol formation.  

PubMed

Organic aerosols are ubiquitous in the atmosphere and play a central role in climate, air quality, and public health. The aerosol size distribution is key in determining its optical properties and cloud condensation nucleus activity. The dominant portion of organic aerosol is formed through gas-phase oxidation of volatile organic compounds, so-called secondary organic aerosols (SOAs). Typical experimental measurements of SOA formation include total SOA mass and atomic oxygen-to-carbon ratio. These measurements, alone, are generally insufficient to reveal the extent to which condensed-phase reactions occur in conjunction with the multigeneration gas-phase photooxidation. Combining laboratory chamber experiments and kinetic gas-particle modeling for the dodecane SOA system, here we show that the presence of particle-phase chemistry is reflected in the evolution of the SOA size distribution as well as its mass concentration. Particle-phase reactions are predicted to occur mainly at the particle surface, and the reaction products contribute more than half of the SOA mass. Chamber photooxidation with a midexperiment aldehyde injection confirms that heterogeneous reaction of aldehydes with organic hydroperoxides forming peroxyhemiacetals can lead to a large increase in SOA mass. Although experiments need to be conducted with other SOA precursor hydrocarbons, current results demonstrate coupling between particle-phase chemistry and size distribution dynamics in the formation of SOAs, thereby opening up an avenue for analysis of the SOA formation process. PMID:23818634

Shiraiwa, Manabu; Yee, Lindsay D; Schilling, Katherine A; Loza, Christine L; Craven, Jill S; Zuend, Andreas; Ziemann, Paul J; Seinfeld, John H

2013-07-16

181

Advanced Experiments in Nuclear Science, Volume I: Advanced Nuclear Physics and Chemistry Experiments.  

ERIC Educational Resources Information Center

The experiments in this manual represent state-of-the-art techniques which should be within the budgetary constraints of a college physics or chemistry department. There are fourteen experiments divided into five modules. The modules are on X-ray fluorescence, charged particle detection, neutron activation analysis, X-ray attenuation, and…

Duggan, Jerome L.; And Others

182

Quantum chemistry simulation on quantum computers: theories and experiments.  

PubMed

It has been claimed that quantum computers can mimic quantum systems efficiently in the polynomial scale. Traditionally, those simulations are carried out numerically on classical computers, which are inevitably confronted with the exponential growth of required resources, with the increasing size of quantum systems. Quantum computers avoid this problem, and thus provide a possible solution for large quantum systems. In this paper, we first discuss the ideas of quantum simulation, the background of quantum simulators, their categories, and the development in both theories and experiments. We then present a brief introduction to quantum chemistry evaluated via classical computers followed by typical procedures of quantum simulation towards quantum chemistry. Reviewed are not only theoretical proposals but also proof-of-principle experimental implementations, via a small quantum computer, which include the evaluation of the static molecular eigenenergy and the simulation of chemical reaction dynamics. Although the experimental development is still behind the theory, we give prospects and suggestions for future experiments. We anticipate that in the near future quantum simulation will become a powerful tool for quantum chemistry over classical computations. PMID:22652702

Lu, Dawei; Xu, Boruo; Xu, Nanyang; Li, Zhaokai; Chen, Hongwei; Peng, Xinhua; Xu, Ruixue; Du, Jiangfeng

2012-07-14

183

INDUSTRIAL POST DOCTORAL SCIENTIST JOB SUMMARY: We require an experienced physical organic chemist with broad  

E-print Network

and final reports. REQUIRED BACKGROUND AND EXPERIENCE: · Ph.D. in Physical Organic Chemistry, Pharmaceutical Chemistry, Medicinal Chemistry, Process Chemistry, Chemical Engineering, or closely related discipline · In depth expertise in physical organic chemistry and the structural characterization of small molecules

Bruck, Jehoshua (Shuki)

184

Ceria-based solid catalysts for organic chemistry.  

PubMed

Ceria has been the subject of thorough investigations, mainly because of its use as an active component of catalytic converters for the treatment of exhaust gases. However, ceria-based catalysts have also been developed for different applications in organic chemistry. The redox and acid-base properties of ceria, either alone or in the presence of transition metals, are important parameters that allow to activate complex organic molecules and to selectively orient their transformation. Pure ceria is used in several organic reactions, such as the dehydration of alcohols, the alkylation of aromatic compounds, ketone formation, and aldolization, and in redox reactions. Ceria-supported metal catalysts allow the hydrogenation of many unsaturated compounds. They can also be used for coupling or ring-opening reactions. Cerium atoms can be added as dopants to catalytic system or impregnated onto zeolites and mesoporous catalyst materials to improve their performances. This Review demonstrates that the exceptional surface (and sometimes bulk) properties of ceria make cerium-based catalysts very effective for a broad range of organic reactions. PMID:20486156

Vivier, Laurence; Duprez, Daniel

2010-06-21

185

Two Methods of Determining Total Phenolic Content of Foods and Juices in a General, Organic, and Biological (GOB) Chemistry Lab  

ERIC Educational Resources Information Center

The determination of total phenolics in foods and fruit juices was used successfully as a laboratory experiment in our undergraduate general, organic, and biological (GOB) chemistry course. Two different colorimetric methods were used over three years and comparative student results indicate that a ferrous ammonium sulfate (FAS) indicator…

Shaver, Lee Alan; Leung, Sam H.; Puderbaugh, Amy; Angel, Stephen A.

2011-01-01

186

The Use of Modular Computer-Based Lessons in a Modification of the Classical Introductory Course in Organic Chemistry.  

ERIC Educational Resources Information Center

An experimental course in organic chemistry utilized computer-assisted instructional (CAI) techniques. The CAI lessons provided tutorial drill and practice and simulated experiments and reactions. The Conversational Language for Instruction and Computing was used, along with a CDC 6400-6600 system; students scheduled and completed the lessons at…

Stotter, Philip L.; Culp, George H.

187

Electrochemical injection of organic corrosion inhibitors into carbonated cementitious materials: Part 1. Effects on pore solution chemistry  

Microsoft Academic Search

This series of investigations was intended to clarify phenomena associated with electrochemical injection of the organic base corrosion inhibitors, ethanolamine and guanidine, into carbonated concrete. In Part 1, experiments were conducted with laminated specimens of carbonated cement paste, that were specially designed to facilitate analysis with adequate spatial resolution to assess changes in their pore solution phase chemistry after they

S. Sawada; J. Kubo; C. L. Page; M. M. Page

2007-01-01

188

Wet Chemistry experiments on the 2007 Phoenix Mars Scout Lander mission: Data analysis and results  

E-print Network

performed using the Wet Chemistry Laboratories on the 2007 Phoenix Mars Scout Lander. One soil sampleWet Chemistry experiments on the 2007 Phoenix Mars Scout Lander mission: Data analysis and results: Kounaves, S. P., et al. (2010), Wet Chemistry experiments on the 2007 Phoenix Mars Scout Lander mission

Kounaves, Samuel P.

189

Analysis of a Distance-Education Program in Organic Chemistry  

NASA Astrophysics Data System (ADS)

Distance education has become a very popular mode for providing education to students who would not otherwise be able to take classes. Although it has been used for lecture courses in chemistry, little is known about its relative effectiveness compared to on-site courses with regard to student performance. This study compared sections of organic chemistry in which distance education was the learning mode with sections that were taught on site. All sections were instructed in a team-teaching format. A local instructor taught the lab sections at all locations and lab reports were forwarded to the on-campus faculty via email. Surveys were prepared and administered to all sections of students for qualitative assessment. The surveys provided information on student attitudes toward distance learning as well as the corresponding lab section, team-teaching techniques, and course Web page. Exam and spatial ability scores were statistically analyzed to determine quantitative differences. The data revealed no statistically significant differences between the performance of the students learning by distance education and those in regular sections.

Kurtz, Martha J.; Holden, Brandt E.

2001-08-01

190

Retrievals for the atmospheric chemistry experiment Fourier-transform spectrometer.  

PubMed

SCISAT-1, also known as the Atmospheric Chemistry Experiment, is a satellite mission for remote sensing of the Earth's atmosphere, launched on 12 August 2003. The primary instrument on the satellite is a 0.02 cm(-1) resolution Fourier-transform spectrometer operating in the mid-IR (750-4400 cm(-1)). We describe the approach developed for the retrieval of atmospheric temperature and pressure from the troposphere to the lower thermosphere as well as the strategy for the retrievals of volume-mixing ratio profiles of atmospheric species. PMID:16318195

Boone, Chris D; Nassar, Ray; Walker, Kaley A; Rochon, Yves; McLeod, Sean D; Rinsland, Curtis P; Bernath, Peter F

2005-11-20

191

Lesson Planner for Demonstrations in Organic Chemistry Videodisc  

NASA Astrophysics Data System (ADS)

Lesson Planner is a Microsoft Excel (1) macro that generates barcodes for video included on the Demonstrations in Organic Chemistry videodisc (2). It allows instructors who do not have computer control capability for their videodisc player, but do have a barcode reader, to prepare customized lessons for use in the classroom or laboratory. There is no need to flip through pages in the documentation manual or photocopy pages of barcodes and physically cut and paste them to follow your lecture notes. Lesson Planner includes a complete list of the demonstrations and all sections and subsections included on the videodisc. You simply select the entire demos, sections, or subsections of demos you want to include in your presentation and add them to a lesson list with a mouse click. Lesson Planner generates a list of your selections with barcodes to access the correct video frames. Simply print a copy of the lesson on a laser printer and you are ready to go.

Surovell, Todd A.

1995-09-01

192

Irradiated Benzene Ice Provides Clues to Meteoritic Organic Chemistry  

NASA Technical Reports Server (NTRS)

Aromatic hydrocarbons account for a significant portion of the organic matter in carbonaceous chondrite meteorites, as a component of both the low molecular weight, solvent-extractable compounds and the insoluble organic macromolecular material. Previous work has suggested that the aromatic compounds in carbonaceous chondrites may have originated in the radiation-processed icy mantles of interstellar dust grains. Here we report new studies of the organic residue made from benzene irradiated at 19 K by 0.8 MeV protons. Polyphenyls with up to four rings were unambiguously identified in the residue by gas chromatography-mass spectrometry. Atmospheric pressure photoionization Fourier transform mass spectrometry was used to determine molecular composition, and accurate mass measurements suggested the presence of polyphenyls, partially hydrogenated polyphenyls, and other complex aromatic compounds. The profile of low molecular weight compounds in the residue compared well with extracts from the Murchison and Orgueil meteorites. These results are consistent with the possibility that solid phase radiation chemistry of benzene produced some of the complex aromatics found in meteorites.

Callahan, Michael Patrick; Gerakines, Perry Alexander; Martin, Mildred G.; Hudson, Reggie L.; Peeters, Zan

2013-01-01

193

Reactive Heterogeneous Chemistry on Organic Aerosols: Two Case Studies  

NASA Astrophysics Data System (ADS)

Two sets of laboratory studies will be discussed to illustrate the impact that heterogeneous chemistry involving tropospheric organic aerosols may have on both the gas-phase composition of the atmosphere and the chemical nature of the particles themselves. In the first case, the reactive uptake coefficient for the hydrolysis of dinitrogen pentoxide (N2O5) on organic aerosols has been measured in an entrained aerosol flow tube coupled to a Chemical-Ionization Mass Spectrometer (CIMS). The general observation is that the reaction on aqueous malonic acid aerosols behaves in an analogous manner to that on aqueous inorganic salts, i.e. the uptake coefficient shows a linear dependence on the particle water content up to 50% relative humidity (RH), at which point the effect saturates. In addition, there is evidence for the kinetics being dependent on both the size of the particles and the levels of dissolved nitrate. By contrast, the N2O5 hydrolysis kinetics on solid azelaic acid particles are too slow to be atmospherically significant, even at 85% RH. In the second case, the kinetics and product yields from the oxidation of liquid oleic acid by ozone have been studied in considerable detail, with emphasis on the quantification of gas-phase products (nonanal) by CIMS and water-soluble species by HPLC/Electrospray-Ionization Mass Spectrometry (azelaic acid, nonanoic acid). The atmospheric importance of these results will be discussed, in particular with respect to the role of organic aerosol oxidation as a source of cloud condensation nuclei.

Abbatt, J.; Braban, C.; Broekhuizen, K.; Thornberry, T.; Thornton, J.

2003-12-01

194

Irradiated benzene ice provides clues to meteoritic organic chemistry  

NASA Astrophysics Data System (ADS)

Aromatic hydrocarbons account for a significant portion of the organic matter in carbonaceous chondrite meteorites, as a component of both the low molecular weight, solvent-extractable compounds and the insoluble organic macromolecular material. Previous work has suggested that the aromatic compounds in carbonaceous chondrites may have originated in the radiation-processed icy mantles of interstellar dust grains. Here we report new studies of the organic residue made from benzene irradiated at 19 K by 0.8 MeV protons. Polyphenyls with up to four rings were unambiguously identified in the residue by gas chromatography-mass spectrometry. Atmospheric pressure photoionization Fourier transform mass spectrometry was used to determine molecular composition, and accurate mass measurements suggested the presence of polyphenyls, partially hydrogenated polyphenyls, and other complex aromatic compounds. The profile of low molecular weight compounds in the residue compared well with extracts from the Murchison and Orgueil meteorites. These results are consistent with the possibility that solid phase radiation chemistry of benzene produced some of the complex aromatics found in meteorites.

Callahan, Michael P.; Gerakines, Perry A.; Martin, Mildred G.; Peeters, Zan; Hudson, Reggie L.

2013-11-01

195

Comparing Recent Organizing Templates for Test Content between ACS Exams in General Chemistry and AP Chemistry  

ERIC Educational Resources Information Center

Two different versions of "big ideas" rooted content maps have recently been published for general chemistry. As embodied in the content outline from the College Board, one of these maps is designed to guide curriculum development and testing for advanced placement (AP) chemistry. The Anchoring Concepts Content Map for general chemistry

Holme, Thomas

2014-01-01

196

Aqueous organic chemistry in the atmosphere: sources and chemical processing of organic aerosols.  

PubMed

Over the past decade, it has become clear that aqueous chemical processes occurring in cloud droplets and wet atmospheric particles are an important source of organic atmospheric particulate matter. Reactions of water-soluble volatile (or semivolatile) organic gases (VOCs or SVOCs) in these aqueous media lead to the formation of highly oxidized organic particulate matter (secondary organic aerosol; SOA) and key tracer species, such as organosulfates. These processes are often driven by a combination of anthropogenic and biogenic emissions, and therefore their accurate representation in models is important for effective air quality management. Despite considerable progress, mechanistic understanding of some key aqueous processes is still lacking, and these pathways are incompletely represented in 3D atmospheric chemistry and air quality models. In this article, the concepts, historical context, and current state of the science of aqueous pathways of SOA formation are discussed. PMID:25609552

McNeill, V Faye

2015-02-01

197

The Determination of the Stereochemistry of Erythro-1,2-Diphenyl-1,2-Ethanediol: An Undergraduate Organic Experiment.  

ERIC Educational Resources Information Center

Describes an undergraduate organic chemistry experiment designed to illustrate the power of nuclear magnetic reasonance spectroscopy in a determination of the configurations at centers of chirality of various isomers of acyclic systems. Provides a background discussion and experimental procedure. (JM)

Rowland, Alex T.

1983-01-01

198

Investigating Titan's Atmospheric Chemistry at Low Temperature with the Titan Haze Simulation Experiment  

NASA Astrophysics Data System (ADS)

Titan, Saturn's largest satellite, possesses a dense atmosphere (1.5 bar at the surface) composed mainly of N2 and CH4. The solar radiation and electron bombardment from Saturn's magnetosphere induces a complex organic chemistry between these two constituents leading to the production of more complex molecules and subsequently to solid aerosols. These aerosols in suspension in the atmosphere form the haze layers giving Titan its characteristic orange color. Since 2004, the instruments onboard the Cassini orbiter have produced large amounts of observational data, unraveling a chemistry much more complex than what was first expected, particularly in Titan's upper atmosphere. Neutral, positively and negatively charged heavy molecules have been detected in the ionosphere of Titan, including benzene (C6H6) and toluene (C6H5CH3). The presence of these critical precursors of polycyclic aromatic hydrocarbon (PAH) compounds suggests that PAHs might play a role in the production of Titan's aerosols. The aim of the Titan Haze Simulation (THS) experiment, developed at the NASA Ames COSmIC facility, is to study the chemical pathways that link the simple molecules resulting from the first steps of the N2-CH4 chemistry to benzene, and to PAHs and nitrogen-containing PAHs (PANHs) as precursors to the production of solid aerosols. In the THS experiment, Titan's atmospheric chemistry is simulated by plasma in the stream of a supersonic expansion. With this unique design, the gas mixture is cooled to Titan-like temperature (~150K) before inducing the chemistry by plasma discharge. Due to the short residence time of the gas in the plasma discharge, the THS experiment can be used to probe the first and intermediate steps of Titan's chemistry by injecting different gas mixtures in the plasma. The products of the chemistry are detected and studied using two complementary techniques: Cavity Ring Down Spectroscopy and Time-Of-Flight Mass Spectrometry. Thin tholin deposits are also produced in the THS experiment and can be analyzed by Gas Chromatography-Mass Spectrometry (GC-MS), Scanning Electron Microscopy (SEM) and IR spectroscopy. Here we present the results of a systematic mass spectrometry study using N2-based, Ar-based and N2-CH4(90:10)-based mixtures with several hydrocarbon precursors to investigate specific pathways associated with the presence of these trace elements in Titan's atmosphere. These results show the uniqueness of the THS experiment to help understand the first and intermediate steps of Titan's atmospheric chemistry as well as specific chemical pathways leading to Titan's haze formation. We will also present the results of ex situ analyses performed on tholins produced in the THS experiment with different gas mixtures, and compare them to tholin films produced in a static photochemistry cell using VUV instead of plasma as the energy source for the chemistry. Acknowledgments This research is supported by NASA SMD (Planetary Atmospheres Program). E.S.O. acknowledges the support of the NASA Postdoctoral Program (NPP) and thanks Claire L. Ricketts for the help and discussions with regard to the photochemistry cell. Finally, the authors acknowledge the technical support of R. Walker (NASA ARC).

Sciamma-O'Brien, E. M.; Salama, F.

2012-12-01

199

Education & Experience B.S. Chemistry, University of California  

E-print Network

of Utah Cheves T. Walling Graduate Research Award (1995) Union Carbide Corp. Kenan Analytical Chemistry Award (1993) David L. Patrick Professor of Chemistry Tel 360-650-3128 Western Washington University Fax

Patrick, David L.

200

A context based approach using Green Chemistry/Bio-remediation principles to enhance interest and learning of organic chemistry in a high school AP chemistry classroom  

NASA Astrophysics Data System (ADS)

The ability of our planet to sustain life and heal itself is not as predictable as it used to be. Our need for educated future scientists who know what our planet needs, and can passionately apply that knowledge to find solutions should be at the heart of science education today. This study of learning organic chemistry through the lens of the environmental problem "What should be done with our food scraps?" explores student interest, and mastery of certain concepts in organic chemistry. This Green Chemistry/ Bio-remediation context-based teaching approach utilizes the Nature MillRTM, which is an indoor food waste composting machine, to learn about organic chemistry, and how this relates to landfill reduction possibilities, and resource production. During this unit students collected food waste from their cafeteria, and used the Nature MillRTM to convert food waste into compost. The use of these hands on activities, and group discussions in a context-based environment enhanced their interest in organic chemistry, and paper chromatography. According to a one-tailed paired T-test, the result show that this context-based approach is a significant way to increase both student interest and mastery of the content.

Miller, Tricia

201

The Integration of Green Chemistry Experiments with Sustainable Development Concepts in Pre-Service Teachers' Curriculum: Experiences from Malaysia  

ERIC Educational Resources Information Center

Purpose: The purpose of this paper is to introduce green chemistry experiments as laboratory-based pedagogy and to evaluate effectiveness of green chemistry experiments in delivering sustainable development concepts (SDCs) and traditional environmental concepts (TECs). Design/methodology/approach: Repeated measure design was employed to evaluate…

Karpudewan, Mageswary; Ismail, Zurida Hg; Mohamed, Norita

2009-01-01

202

Message of Welcome The Organic Chemistry Department of Alicante University was established in 1990. Since then, it is involved in  

E-print Network

Message of Welcome The Organic Chemistry Department of Alicante University was established in 1990. Since then, it is involved in the teaching and research of the organic chemistry area. Among the forty PhD theses per year. The Organic Chemistry Department laboratories are fully-equipped to perform high

Escolano, Francisco

203

Students' Understanding of Acids/Bases in Organic Chemistry Contexts  

ERIC Educational Resources Information Center

Understanding key foundational principles is vital to learning chemistry across different contexts. One such foundational principle is the acid/base behavior of molecules. In the general chemistry sequence, the Bronsted-Lowry theory is stressed, because it lends itself well to studying equilibrium and kinetics. However, the Lewis theory of…

Cartrette, David P.; Mayo, Provi M.

2011-01-01

204

The ACS Exams Institute Undergraduate Chemistry Anchoring Concepts Content Map II: Organic Chemistry  

ERIC Educational Resources Information Center

As a way to assist chemistry departments with programmatic assessment of undergraduate chemistry curricula, the ACS Examinations Institute is devising a map of the content taught throughout the undergraduate curriculum. The structure of the map is hierarchal, with large grain size at the top and more content detail as one moves "down"…

Raker, Jeffrey; Holme, Thomas; Murphy, Kristen

2013-01-01

205

An Undergraduate Laboratory Experiment in Bioinorganic Chemistry: Ligation States of Myoglobin  

ERIC Educational Resources Information Center

Although there are numerous inorganic model systems that are readily presented as undergraduate laboratory experiments in bioinorganic chemistry, there are few examples that explore the inorganic chemistry of actual biological molecules. We present a laboratory experiment using the oxygen-binding protein myoglobin that can be easily incorporated…

Bailey, James A.

2011-01-01

206

Chemical Remediation of Nickel(II) Waste: A Laboratory Experiment for General Chemistry Students  

ERIC Educational Resources Information Center

This project involved developing a method to remediate large quantities of aqueous waste from a general chemistry laboratory experiment. Aqueous Ni(II) waste from a general chemistry laboratory experiment was converted into solid nickel hydroxide hydrate with a substantial decrease in waste volume. The remediation method was developed for a…

Corcoran, K. Blake; Rood, Brian E.; Trogden, Bridget G.

2011-01-01

207

An Online Tutorial for SciFinder for Organic Chemistry Classes  

Microsoft Academic Search

An online tutorial for SciFinder, the premier database for searching the chemical literature, was created by a team consisting of the science librarian, the systems librarian, and a chemistry professor at Rider University using Adobe Captivate 4 software. It was then used by two sections of an Organic Chemistry class during the spring 2010 semester. Traditionally, the science librarian has

Patricia H. Dawson; Danielle L. Jacobs; Sharon Q. Yang

2010-01-01

208

Letters to Analytical Chemistry Metal-Organic Framework Thin Film for Enhanced  

E-print Network

Letters to Analytical Chemistry Metal-Organic Framework Thin Film for Enhanced Localized Surface of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 Despite its high refractive; in particular, LSPR spectroscopy could be utilized to detect hazardous or toxic gases and manage industrial

209

A Simple Assignment that Enhances Students' Ability to Solve Organic Chemistry Synthesis Problems and Understand Mechanisms  

ERIC Educational Resources Information Center

Organic chemistry students typically struggle with the retrosynthetic approach to solving synthesis problems because most textbooks present the chemistry grouped by "reactions of the functional group". In contrast, the retrosynthetic approach requires the student to envision "reactions that yield the functional group". A second challenge is the…

Teixeira, Jennifer; Holman, R. W.

2008-01-01

210

An Asymptotic Approach to the Development of a Green Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

Green chemistry is the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture and application of chemical products. Some of the philosophical questions and practical decisions that have guided the greening of the organic chemistry laboratory at Hendrix College in…

Goodwin, Thomas E.

2004-01-01

211

The Kinetics and Thermodynamics of the Phenol from Cumene Process: A Physical Chemistry Experiment.  

ERIC Educational Resources Information Center

Presents a physical chemistry experiment demonstrating the differences between thermodynamics and kinetics. The experiment used the formation of phenol and acetone from cumene hydroperoxide, also providing an example of an industrially significant process. (CS)

Chen, Edward C. M.; Sjoberg, Stephen L.

1980-01-01

212

ATR-FTIR Spectroscopy in the Undergraduate Chemistry Laboratory: Part II--A Physical Chemistry Laboratory Experiment on Surface Adsorption  

ERIC Educational Resources Information Center

Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy is a useful technique for measuring the infrared spectra of solids and liquids as well as probing adsorption on particle surfaces. The use of FTIR-ATR spectroscopy in organic and inorganic chemistry laboratory courses as well as in undergraduate research was presented…

Schuttlefield, Jennifer D.; Larsen, Sarah C.; Grassian, Vicki H.

2008-01-01

213

An Experiment to Quantitate Organically Bound Phosphate.  

ERIC Educational Resources Information Center

Describes quick and easy experiments that yield quantitative information on a variety of levels, emphasize the concept of experimental controls, and integrate the experimental with the theoretical using the organic phosphates as the experimental system. Background information, list of materials needed, and procedures used are included. (JN)

Palmer, Richard E.

1985-01-01

214

Simulations as real-time integration of information: "Covalence", an Organic Chemistry game  

NASA Astrophysics Data System (ADS)

College-level Organic Chemistry classes can be overwhelming to their students. In addition to learning a relatively large amount of information, students have to learn to read multiple visual models and use them to understand subtle differences in the science. In making the puzzle game Covalence to address Organic Chemistry education, I decided to focus on three aspects of the subject's education -- Hidden information in the various visual models, the lack of integration of these representations into a 3D representation of Chemical phenomena, and an atom-based view of the molecules and how they contribute to the field's subtle issues. This paper discusses various traditional visual models taught in Organic Chemistry classes, devising a new visual model to bring out hidden information in these traditional models, and designing levels based on known reactions and their consequences, to illustrate Organic Chemistry's elegance and subtlety.

Mathias, Jason

215

Microwave-Assisted Chemistry: A Rapid and Sustainable Route to Synthesis of Organics and Nanomaterials  

EPA Science Inventory

The use of emerging MW-assisted chemistry techniques in conjunction with benign reaction media is dramatically reducing chemical waste and reaction times in several organic syntheses and chemical transformations. This review summarizes recent developments in MW-assisted synthesis...

216

Organic nitrogen chemistry during low-grade metamorphism Jean-Paul Boudou  

E-print Network

Organic nitrogen chemistry during low-grade metamorphism Jean-Paul Boudou a *, Arndt Schimmelmann b@ccr.jussieu.fr Abstract - Most of the organic nitrogen (Norg) on Earth is disseminated in crustal sediments and rocks in the form of fossil nitrogen-containing organic matter. The chemical speciation of fossil Norg within

Paris-Sud XI, Université de

217

Exploring organic chemistry in planet-forming zones  

NASA Astrophysics Data System (ADS)

Context. Over the last few years, the chemistry of molecules other than CO in the planet-forming zones of disks is starting to be explored with Spitzer and high-resolution ground-based data. However, these studies have focused only on a few simple molecules. Aims: The aim of this study is to put observational constraints on the presence of more complex organic and sulfur-bearing molecules predicted to be abundant in chemical models of disks and to simulate high resolution spectra in view of future missions. Methods: High signal-to-noise ratio (S/N) Spitzer spectra of the near edge-on disks IRS 46 and GV Tau are used to search for mid-infrared absorption bands of various molecules. These disks are good laboratories because absorption studies do not suffer from low line/continuum ratios that plague emission data. Simple local thermodynamic equilibrium (LTE) slab models are used to infer column densities (or upper limits) and excitation temperatures. Results: Mid-infrared bands of HCN, C2H2 and CO2 are clearly detected toward both sources. The HCN and C2H2 absorption arises in warm gas with excitation temperatures of 400-700 K, whereas the CO2 absorption originates in cooler gas of ~250 K. Column densities and their ratios are comparable for the two sources. No other absorption features are detected at the 3? level. Column density limits of the majority of molecules predicted to be abundant in the inner disk - C2H4, C2H6, C6H6, C3H4, C4H2, CH3, HNC, HC3N, CH3CN, NH3 and SO2 - are determined and compared with disk models. Conclusions: The inferred abundance ratios and limits with respect to C2H2 and HCN are roughly consistent with models of the chemistry in high temperature gas. Models of UV irradiated disk surfaces generally agree better with the data than pure X-ray models. The limit on NH3/HCN implies that evaporation of NH3-containing ices is only a minor contributor. The inferred abundances and their limits also compare well with those found in comets, suggesting that part of the cometary material may derive from warm inner disk gas. The high resolution simulations show that future instruments on the James Webb Space Telescope (JWST), the Extremely Large Telescopes (ELTs), the Stratospheric Observatory for Infrared Astronomy (SOFIA) and the Space Infrared Telescope for Cosmology and Astrophysics (SPICA) can probe up to an order of magnitude lower abundance ratios and put important new constraints on the models, especially if pushed to high S/Ns. Appendices are available in electronic form at http://www.aanda.org

Bast, J. E.; Lahuis, F.; van Dishoeck, E. F.; Tielens, A. G. G. M.

2013-03-01

218

Geothermal injection treatment: process chemistry, field experiences, and design options  

SciTech Connect

The successful development of geothermal reservoirs to generate electric power will require the injection disposal of approximately 700,000 gal/h (2.6 x 10/sup 6/ 1/h) of heat-depleted brine for every 50,000 kW of generating capacity. To maintain injectability, the spent brine must be compatible with the receiving formation. The factors that influence this brine/formation compatibility and tests to quantify them are discussed in this report. Some form of treatment will be necessary prior to injection for most situations; the process chemistry involved to avoid and/or accelerate the formation of precipitate particles is also discussed. The treatment processes, either avoidance or controlled precipitation approaches, are described in terms of their principles and demonstrated applications in the geothermal field and, when such experience is limited, in other industrial use. Monitoring techniques for tracking particulate growth, the effect of process parameters on corrosion and well injectability are presented. Examples of brine injection, preinjection treatment, and recovery from injectivity loss are examined and related to the aspects listed above.

Kindle, C.H.; Mercer, B.W.; Elmore, R.P.; Blair, S.C.; Myers, D.A.

1984-09-01

219

Chemistry  

NSDL National Science Digital Library

Finds ChemEd DL resources related to the sections of the General Chemistry textbook, Chemistry, by Kenneth W. Whitten, Raymond E. Davis, M. Larry Peck, George G. Stanley published by Brooks/Cole, 2010.

220

An expert performance approach to examining factors contributing to academic success in organic chemistry  

NASA Astrophysics Data System (ADS)

Successful completion of the introductory course in organic chemistry is a prerequisite for many graduate and professional science programs, yet the failure rate for this course is notoriously high. To date, there have been few studies examining factors contributing to academic success in organic chemistry. This study demonstrates that the online, longitudinal methods used by investigations of expert performance can examine and successfully identify factors contributing to academic success at the college level. Sixty-four students enrolled in introductory organic chemistry during the Fall 2007 and Spring 2008 semesters completed motivation questionnaires, interviews, diaries, and think-aloud reading and problem-solving tasks at three different points across a semester. Measures of spatial ability, general ability, and background preparation were also collected. Each measure was analyzed to determine significant differences between groups differing in grade-point average (GPA) prior to the start of the course and to identify predictors of organic chemistry grade. Variables measuring background preparation, problem-solving strategies and studying strategies were found to be the best predictors of academic success in organic chemistry. Implications for instruction in organic chemistry and effective studying behaviors are discussed.

Nandagopal, Kiruthiga

221

Laboratory Experiment Investigating the Impact of Ocean Acidification on Calcareous Organisms  

ERIC Educational Resources Information Center

The increase in ocean acidity since preindustrial times may have deleterious consequences for marine organisms, particularly those with calcareous structures. We present a laboratory experiment to investigate this impact with general, introductory, environmental, and nonmajors chemistry students. For simplicity and homogeneity, calcite was…

Perera, Alokya P.; Bopegedera, A. M. R. P.

2014-01-01

222

Usnic Acid and the Intramolecular Hydrogen Bond: A Computational Experiment for the Organic Laboratory  

ERIC Educational Resources Information Center

A computational experiment is described for the organic chemistry laboratory that allows students to estimate the relative strengths of the intramolecular hydrogen bonds of usnic and isousnic acids, two related lichen secondary metabolites. Students first extract and purify usnic acid from common lichens and obtain [superscript 1]H NMR and IR…

Green, Thomas K.; Lane, Charles A.

2006-01-01

223

Size distribution dynamics reveal particle-phase chemistry in organic aerosol formation  

NASA Astrophysics Data System (ADS)

Organic aerosols are ubiquitous in the atmosphere and play a central role in climate, air quality and public health. The aerosol size distribution is key in determining its optical properties and cloud condensation nucleus activity. The dominant portion of organic aerosol is formed through gas-phase oxidation of volatile organic compounds, so-called secondary organic aerosol (SOA). Typical experimental measurements of SOA formation include total SOA mass and atomic oxygen-to-carbon ratio. These measurements, alone, are generally insufficient to reveal the extent to which condensed-phase reactions occur in conjunction with the multi-generation gas-phase photooxidation. Combining laboratory chamber experiments and kinetic gas-particle modeling for the dodecane SOA system, here we show that the presence of particle-phase chemistry is reflected in the evolution of the SOA size distribution as well as its mass concentration. Particle-phase reactions are predicted to occur mainly at the particle surface and the reaction products contribute more than half of the SOA mass. Chamber photooxidation with a mid-experiment aldehyde injection confirms that heterogeneous reaction of aldehydes with organic hydroperoxides forming peroxyhemiacetals can lead to a large increase in SOA mass. The results of the current work have a number of implications for SOA models. While the dynamics of an aerosol size distribution reflects the mechanism of growth, we demonstrate here that it provides a key constraint in interpreting laboratory and ambient SOA formation. This work, although carried out specifically for the long chain alkane, dodecane, is expected to be widely applicable to other major classes of SOA precursors. SOA consists of a myriad of organic compounds containing various functional groups, which can generally undergo heterogeneous/multiphase reactions forming low-volatility products such as oligomers and other high molecular mass compounds. If particle-phase chemistry is indeed central to SOA growth in general, the size-resolved SOA formation is better described in terms of kinetically limited condensational growth, rather than solely by thermodynamic equilibrium partitioning.

Shiraiwa, M.; Yee, L. D.; Schilling, K.; Loza, C. L.; Craven, J. S.; Zuend, A.; Ziemann, P. J.; Seinfeld, J.

2013-12-01

224

Aqueous chemistry and yields of secondary organic aerosol formed from glyoxal and methylglyoxal in atmospheric waters  

NASA Astrophysics Data System (ADS)

Atmospherically abundant, volatile, water soluble organic compounds formed through gas-phase oxidation (e.g., glyoxal, methylglyoxal, and acetic acid) have great potential to form secondary organic aerosol via aqueous chemistry (SOAaq) in clouds, fogs and wet aerosols. In this work, detailed reaction mechanisms and a full kinetic model were developed for aqueous OH radical oxidation of methylglyoxal and acetic acid; they were validated, in part, with laboratory experiments (Tan et al., 2012). This new model was combined with the previous glyoxal model (Lim et al., 2010), and used to simulate atmospheric concentration dynamics and estimate SOAaq yields. At cloud relevant concentrations, the major photooxidation products are oxalic and pyruvic acids, and simulated molar SOA yields are ~76-77% for glyoxal and ~64-65% for methylglyoxal, regardless of our assumptions regarding the continued production of precursor (i.e., for both batch and continuously stirred tank reactor assumptions). In the presence of ammonium ion, organic acid salt formation is expected to decrease product vapor pressures and increase SOA yields. In the concentrated solutions encountered in wet aerosols, oligomers form via organic radical-radical reactions; simulated molar SOA yields are ~40% for both glyoxal and methylglyoxal.

Lim, Y. B.; Tan, Y.; Ortiz-Montalvo, D. L.; Turpin, B. J.

2012-12-01

225

Organism support for life sciences spacelab experiments  

NASA Technical Reports Server (NTRS)

This paper presents an overview of the U.S. life sciences laboratory concepts envisioned for the Shuttle/Spacelab era. The basic development approach is to provide a general laboratory facility supplemented by specific experiment hardware as required. The laboratory concepts range from small carry-on laboratories to fully dedicated laboratories in the Spacelab pressurized module. The laboratories will encompass a broad spectrum of research in biology and biomedicine requiring a variety of research organisms. The environmental control and life support of these organisms is a very important aspect of the success of the space research missions. Engineering prototype organism habitats have been designed and fabricated to be compatible with the Spacelab environment and the experiment requirements. These first-generation habitat designs and their subsystems have supported plants, cells/tissues, invertebrates, and small vertebrates in limited evaluation tests. Special handling and transport equipment required for the ground movement of the experiment organisms at the launch/landing site have been built and tested using these initial habitat prototypes.

Drake, G. L.; Heppner, D. B.

1976-01-01

226

Using the QCPE Holdings in Chemical Education: Molecular Models in the Organic Chemistry Laboratory.  

ERIC Educational Resources Information Center

Discusses a successfully implemented laboratory experiment that compares the strengths and weaknesses of mechanical and computer models. The computer models used are available from the Quantum Chemistry Program Exchange (QCPE) at a modest price. (JN)

Lipkowitz, Kenny

1984-01-01

227

Motivational Beliefs and Learning Strategies in Organic Chemistry  

ERIC Educational Resources Information Center

Students enter college chemistry courses with different sources of motivation, appropriate or inappropriate assumptions about their probability of success and how to study. This study is theoretically aligned with self-regulated learning research. Clearly, academic performance is closely related to student motivational beliefs and learning…

Lynch, Douglas Jay; Trujillo, Hernando

2011-01-01

228

Students Doing Chemistry: A Hand-On Experience for K-12  

ERIC Educational Resources Information Center

A hands-on, minds-on inquiry chemistry experiment was developed for use in K-12 schools that enables students to combine the chemicals of their choice and observe the results. The chemistry involved is water based and builds upon acid-base, double displacement, and iodometric detection of starch reactions. Chemicals readily available in the…

Selco, Jodye I.; Bruno, Mary; Chan, Sue

2012-01-01

229

The Atmospheric Chemistry Experiment (ACE): overview of the ACE Validation Program  

Microsoft Academic Search

The ACE Validation Program is a program of validation comparison studies designed to continue throughout the life of the mission. The initial phase has been completed recently with the submission of papers for a special issue of Atmospheric Chemistry and Physics - Validation results for the Atmospheric Chemistry Experiment (ACE). These studies provided results for O3 , H2 O, CO,

Kaley Walker

2008-01-01

230

Incorporating Guided-Inquiry Learning into the Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

Guided-inquiry experiments also known as discovery-based experiments, which combine the pedagogical advantages of open-inquiry methods with the practical advantages of expository experiments, are described. Unlike open-inquiry or problem-based experiments, guided-inquiry experiments could be readily adapted to large laboratory sections and induces…

Gaddis, Barbara A.; Schoffstall, Allen M.

2007-01-01

231

Modeling SOAaq Formation: Explicit Organic Chemistry in Cloud Droplets with CMAQ  

NASA Astrophysics Data System (ADS)

Aqueous multiphase chemistry in the atmosphere has a substantial impact on climate and can lead to air quality changes that adversely impact human health and the environment. The chemistry is complex because of the variety of compounds present in the atmosphere and the phase transitions associated with multiphase reactions. These reactions can lead to the formation of secondary organic aerosols (SOAAQ) in the atmosphere. When included, current photochemical models typically use a simple parameterization to describe SOAAQ formation. Here, we discuss the implementation of explicit aqueous SOA chemistry in a box model of the CMAQ 5.0.1 aqueous phase chemistry mechanism using the Kinetic PreProcessor (KPP). The expanded chemistry model includes reactions of glyoxal, methylglyoxal, and glycolaldehyde as precursors to form SOAAQ and is based on the mechanism from Lim et. al. 2010. The current aqueous phase chemistry module in CMAQ uses a forward Euler method to solve the system of oxidation equations, estimating the pH with a bisection method assuming electroneutrality, and multiphase processes are solved sequentially. This is not robust for systems with large dynamic range (e.g., multiphase systems), and inhibits expansion of the aqueous phase chemical mechanism to adequately incorporate the growing body of literature that describes multiphase organic chemistry. The KPP solver allows for all processes to be solved simultaneously and facilitates expansion of the current mechanism. Addition of explicit organic reactions and H2O2 photolysis in the KPP box model results in increased mass of organic aerosol and more realistic predictions. For particulate matter focused air quality management strategies to be effective, it is important that models move away from the yield-based approach currently used and expand to include more explicit organic chemistry.

Carlton, A. G.; Sareen, N.; Fahey, K.; Hutzell, W. T.

2013-12-01

232

Synthesis of Organic Matter of Prebiotic Chemistry at the Protoplanetary Disc  

NASA Astrophysics Data System (ADS)

We have carried out scanning electron microscopic examination of CM carbonaceous chondrites meteorites Migey, Murchison, Staroe Boriskino aged more than 4.56 billion years (about 50 million years from the beginning of the formation of the Solar system). Our study confirmed the conclusion of Rozanov, Hoover and other researchers about the presence of microfossils of bacterial origin in the matrix of all these meteorites. Since the time of the Solar system formation is 60 - 100 million years, the primary biocenosis emerged in the protoplanetary disc of the Solar system before meteorites or simultaneously with them. It means that prebiological processes and RNA world appeared even earlier in the circumsolar protoplanetary disc. Most likely, this appearance of prebiotic chemistry takes place nowday in massive and medium-massive discs of the observed young stellar objects (YSO) class 0 and I. The timescale of the transition from chemical to biological evolution took less than 50 million years for the Solar system. Further evolution of individual biocenosis in a protoplanetary disc associated with varying physico-chemical conditions during the formation of the Solar system bodies. Biocenosis on these bodies could remove or develop under the influence of many cosmic factors and geological processes in the case of Earth. To complete the primary biosphere formation in short evolution time - millions of years - requires highly efficient chemical syntheses. In industrial chemistry for the efficient synthesis of ammonia, hydrogen cyanide, methanol and other organic species, that are the precursors to obtain prebiotic compounds, catalytic reactors of high pressure are used. Thus (1) necessary amount of the proper catalyst in (2) high pressure areas of the disc can trigger these intense syntheses. The disc contains the solids with the size from nanoparticle to pebble. Iron and magnesium is catalytically active ingredient for such solids. The puzzle is a way to provide hydrogen pressure inside the disc from tens to hundred atmospheres. We simulated unsteady processes in massive circumstellar discs around YSO class O and I. In the computational experiments, we have shown that at a certain stage of its evolution the circumstellar discs of gas and solids produces local areas of high pressure. According to the classical heterogeneous catalysis, a wide range of organic and prebiotic compounds could have been synthesized in these areas. Can we capture these areas of high pressure synthesis in observation of circumstellar discs? Due to the small sizes of such areas they can be hardly ever resolved even with the modern telescopes such as ALMA. However, we can try to detect their signatures in the disc, since the gas of the disc keep the set of organic synthesis products. The idea is to define the signature of the process using laboratory experiments. Varying gas temperature and pressure in laboratory setup we can carry out the catalytic high pressure syntheses and specify the set of gaseous products. These sets of organic compounds observed in the discs may serve as indicators of the emergence of high-pressure areas of prebiotic chemistry. Thus, there is a special interest to the study of YSO class 0 and I by means of observational astronomy. For these objects, first data on the presence of individual organic compounds in massive hydrogen-helium component of the discs appear. The origin of the organic compounds that are associated with chemical reactions in the discs should be separated from the set of organic compounds of the initial molecular cloud.

Snytnikov, Valeriy; Stoynovskaya, Olga; Rudina, Nina

233

Structure & Reactivity in Organic, Biological and Inorganic Chemistry  

NSDL National Science Digital Library

This site is a collection of web-pages designed to support an integrated treatment of related topics from organic, inorganic and biochemistry. The topics are organized around common principles of structure or reactivity.

Chris P. Schaller

234

Developing Problem-Solving Skills through Retrosynthetic Analysis and Clickers in Organic Chemistry  

ERIC Educational Resources Information Center

A unique approach to teaching and learning problem-solving and critical-thinking skills in the context of retrosynthetic analysis is described. In this approach, introductory organic chemistry students, who typically see only simple organic structures, undertook partial retrosynthetic analyses of real and complex synthetic targets. Multiple…

Flynn, Alison B.

2011-01-01

235

A Mass Spectral Chlorine Rule for Use in Structure Determinations in Sophomore Organic Chemistry  

ERIC Educational Resources Information Center

The low-resolution mass spectrum of integral masses is used to determine the number of bromine and chlorine atoms in an organic compound. The chlorine rule is a tool suitable for use in structural determinations in first year organic chemistry and it is supported by the ability of sophomore-level students to successfully determine n and m from the…

Gross, Ray A., Jr.

2004-01-01

236

The Role of Spatial Ability and Strategy Preference for Spatial Problem Solving in Organic Chemistry  

ERIC Educational Resources Information Center

In organic chemistry, spatial reasoning is critical for reasoning about spatial relationships in three dimensions and representing spatial information in diagrams. Despite its importance, little is known about the underlying cognitive components of spatial reasoning and the strategies that students employ to solve spatial problems in organic

Stieff, Mike; Ryu, Minjung; Dixon, Bonnie; Hegarty, Mary

2012-01-01

237

Ligand chemistry of titania precursor affects transient photovoltaic behavior in inverted organic solar cells  

E-print Network

transient photovoltaic behavior in inverted organic solar cells Jong Bok Kim,1,a) Seokhoon Ahn,2,b) Seok JuLigand chemistry of titania precursor affects transient photovoltaic behavior in inverted organic solar cells Jong Bok Kim, Seokhoon Ahn, Seok Ju Kang, Colin Nuckolls, and Yueh-Lin Loo Citation: Appl

Hone, James

238

Selective Bifunctional Modification of a Non-catenated Metal-Organic Framework Material via 'Click' Chemistry  

SciTech Connect

A noncatenated, Zn-based metal-organic framework (MOF) material bearing silyl-protected acetylenes was constructed and postsynthetically modified using 'click' chemistry. Using a solvent-based, selective deprotection strategy, two different organic azides were 'clicked' onto the MOF crystals, resulting in a porous material whose internal and external surfaces are differently functionalized.

Gadzikwa, Tendai; Farha, Omar K.; Malliakas, Christos D.; Kanatzidis, Mercouri G.; Hupp, Joseph T.; Nguyen, SonBinh T.; NWU

2009-12-01

239

MOTIVATIONAL BELIEFS AND LEARNING STRATEGIES IN ORGANIC CHEMISTRY  

Microsoft Academic Search

Students enter college chemistry courses with different sources of motivation, appropriate or inappropriate assumptions about\\u000a their probability of success and how to study. This study is theoretically aligned with self-regulated learning research.\\u000a Clearly, academic performance is closely related to student motivational beliefs and learning strategies. This study investigated\\u000a the motivational beliefs and learning strategies of 2 years of college students in

Douglas Jay Lynch; Hernando Trujillo

240

A Solid State Chemistry Experiment: Dislocations in Etched Calcite by Polaroid Photomicrography  

ERIC Educational Resources Information Center

Suggests that adequate attention should be given to lattice imperfections in teaching solid state chemistry. Some concepts to be included in such a program are explained. An experiment to be performed by undergraduates on photomicrography is described in detail. (PS)

Agnew, N. H.

1972-01-01

241

Imidazole as a pH Probe: An NMR Experiment for the General Chemistry Laboratory  

ERIC Educational Resources Information Center

The analysis describes an NMR experiment for the general chemistry laboratory, which employs an unknown imidazole solution to measure the pH values. The described mechanism can also be used for measuring the acidity within the isolated cells.

Hagan, William J., Jr.; Edie, Dennis L.; Cooley, Linda B.

2007-01-01

242

Cross-Disciplinary Thermoregulation and Sweat Analysis Laboratory Experiences for Undergraduate Chemistry and Exercise Science Students  

NSDL National Science Digital Library

This article describes a qualitative evaluation of Cross-Disciplinary health sciences undergraduate laboratory experiences in which concepts and students from two distinct disciplines (chemistry and exercise physiology) combined to study exercise thermoregulation and sweat analysis.

2011-06-01

243

Bridging Native American Culture and Chemistry: Gas Chromatography Experiments That Examine Native Foods.  

ERIC Educational Resources Information Center

Describes three chemistry experiments that link common foodstuffs traditionally and currently harvested by Native Americans in different parts of North America to modern chemical instrumentation and discovery methods. (CCM)

Sykes, Andrew G.; Caple, Gerald

1999-01-01

244

Photochemical Reactions of Tris (Oxalato) Iron (III): A First-Year Chemistry Experiment.  

ERIC Educational Resources Information Center

Describes a first-year chemistry experiment that illustrates the fundamental concepts of a photoinduced reaction. Qualitative and quantitative parts of the photoreduction of potassium ferrioxalate are detailed. (CS)

Baker, A. D.; And Others

1980-01-01

245

Determination of Rate Constants for Ouabain Inhibition of Adenosine Triphosphatase: An Undergraduate Biological Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

Describes an undergraduate biological chemistry laboratory experiment which provides students with an example of pseudo-first-order kinetics with the cardiac glycoside inhibition of mammalism sodium and potassium transport. (SL)

Sall, Eri; And Others

1978-01-01

246

Minimal Impact of Organic Chemistry Prerequisite on Student Performance in Introductory Biochemistry  

PubMed Central

Curriculum design assumes that successful completion of prerequisite courses will have a positive impact on student performance in courses that require the prerequisite. We recently had the opportunity to test this assumption concerning the relationship between completion of the organic chemistry prerequisite and performance in introductory biochemistry. We found no statistically significant differences between average biochemistry grades or grade distribution among students with or without the organic chemistry prerequisite. However, students who had not completed the organic chemistry prerequisite before biochemistry were more likely to withdraw from the course than those who had completed the prerequisite. In contrast to the lack of correlation between performance in biochemistry and completion of organic chemistry, we observed a strong, highly significant positive relationship between cumulative GPA and the biochemistry grade. Our data suggest that excluding students without organic chemistry would have less positive impact on student success in biochemistry than would providing additional support for all students who enroll in biochemistry with a cumulative GPA below 2.5. PMID:19255135

Cotner, Sehoya; Winkel, Amy

2009-01-01

247

A Novel W-Tube for Microscale Experiments in Chemistry  

ERIC Educational Resources Information Center

A simple W-shaped apparatus was developed by bending glass tubing to contain all of the chemicals involved and to limit the quantities to microscale. The W-tubes were tested by the teachers and students from a few schools to demonstrate its great utility and convenience in microscale chemistry laboratory.

Gupta, H. O.

2007-01-01

248

Theoretical Chemistry Comes Alive: Full Partner with Experiment.  

ERIC Educational Resources Information Center

The expected thrust for theoretical chemistry in the next decade will be to combine knowledge of fundamental chemical steps/interactions with advances in chemical dynamics, irreversible statistical mechanics, and computer technology to produce simulations of chemical systems with reaction site competition. A sample simulation (using the enzyme…

Goddard, William A., III

1985-01-01

249

Demystifying Introductory Chemistry. Part 1: Electron Configurations from Experiment.  

ERIC Educational Resources Information Center

Presents suggestions for alternative presentations of some of the material that usually forms part of the introductory chemistry course. Emphasizes development of concepts from experimental results. Discusses electronic configurations and quantum numbers, experimental evidence for electron configurations, deducing the shell model from the periodic…

Gillespie, Ronald J.; And Others

1996-01-01

250

Stereoisomerism in Coordination Chemistry: A Laboratory Experiment for Undergraduate Students.  

ERIC Educational Resources Information Center

Describes an experimental procedure to acquaint inorganic chemistry students with stereochemical concepts using tris-(2,3-butanediamine)cobalt(III). Notes two isomeric forms exist and both form metal chelates. Separation is accomplished by chromatography and analysis is by NMR and infrared spectroscopy. Provides spectra of isomers. (MVL)

Gargallo, Maria Fe; And Others

1988-01-01

251

Preparation of Gold Nanoparticles Using Tea: A Green Chemistry Experiment  

ERIC Educational Resources Information Center

Assimilating green chemistry principles in nanotechnology is a developing area of nanoscience research nowadays. Thus, there is a growing demand to develop environmentally friendly and sustainable methods for the synthesis of nanoparticles that utilize nontoxic chemicals, environmentally benign solvents, and renewable materials to avoid their…

Sharma, R. K.; Gulati, Shikha; Mehta, Shilpa

2012-01-01

252

Looking beyond Lewis Structures: A General Chemistry Molecular Modeling Experiment Focusing on Physical Properties and Geometry  

ERIC Educational Resources Information Center

We present a guided-inquiry experiment using Spartan Student Version, ready to be adapted and implemented into a general chemistry laboratory course. The experiment provides students an experience with Spartan Molecular Modeling software while discovering the relationships between the structure and properties of molecules. Topics discussed within…

Linenberger, Kimberly J.; Cole, Renee S.; Sarkar, Somnath

2011-01-01

253

The Oil Drop Experiment: Do Physical Chemistry Textbooks Refer to Its Controversial Nature?  

ERIC Educational Resources Information Center

Most general chemistry textbooks consider the oil drop experiment as a classic experiment, characterized by its simplicity and precise results. A review of the history and philosophy of science literature shows that the experiment is difficult to perform (even today!) and generated a considerable amount of controversy. Acceptance of the…

Niaz, Mansoor; Rodriguez, Maria A.

2005-01-01

254

A study of how precursor key concepts for organic chemistry success are understood by general chemistry students  

NASA Astrophysics Data System (ADS)

This study examines college student understanding of key concepts that will support future organic chemistry success as determined by university instructors. During four one-hour individual interviews the sixteen subjects attempted to solve general chemistry problems. A think-aloud protocol was used along with a whiteboard where the students could draw and illustrate their ideas. The protocols for the interviews were adapted from the Covalent Structure and Bonding two-tiered multiple choice diagnostic instrument (Peterson, Treagust, & Garnett, 1989) and augmented by the Geometry and Polarity of Molecules single-tiered multiple choice instrument (Furio & Calatayud, 1996). The interviews were videotaped, transcribed, and coded for analysis to determine the subjects' understanding of the key ideas. The subjects displayed many misconceptions that were summarized into nine assertions about student conceptualization of chemistry. (1) Many students misunderstand the location and nature of intermolecular forces. (2) Some think electronegativity differences among atoms in a molecule are sufficient to make the molecule polar, regardless of spatial arrangement. (3) Most know that higher phase change temperatures imply stronger intermolecular attractions, but many do not understand the difference between covalent molecular and covalent network substances. (4) Many have difficulty deciding whether a molecule is polar or non-polar, often confusing bilateral symmetry with spatial symmetry in all three dimensions. (5) Many cannot reliably draw correct Lewis structures due to carelessness and overuse of flawed algorithms. (6) Many are confused by how electrons can both repel one other and facilitate bonding between atoms via orbitals---this seems oxymoronic to them. (7) Many cannot explain why the atoms of certain elements do not follow the octet rule and some believe the octet rule alone can determine the shape of a molecule. (8) Most do know that electronegativity and polarity are not adequate to determine the shape of a molecule---but some apply the VSEPR theory in incorrect ways. (9) Students do not reason significantly differently when working with various representations of molecules such as ball-and-stick models, molecular formulas, and Lewis structures. The study illuminated specific parts of the general chemistry curriculum that are particularly troublesome for students but necessary for their further achievement in chemistry. This information is important; it gives the discipline of chemistry education target areas to focus on for general chemistry pedagogical improvement efforts.

Meyer, Patrick Gerard

255

Developments in Analytical Chemistry: Acoustically Levitated Drop Reactors for Enzyme Reaction Kinetics and Single-Walled Carbon Nanotube-Based Sensors for Detection of Toxic Organic Phosphonates  

ERIC Educational Resources Information Center

Developments in analytical chemistry were made using acoustically levitated small volumes of liquid to study enzyme reaction kinetics and by detecting volatile organic compounds in the gas phase using single-walled carbon nanotubes. Experience gained in engineering, electronics, automation, and software development from the design and…

Field, Christopher Ryan

2009-01-01

256

Spatial organization of stream water discharge and chemistry in forested headwaters  

NASA Astrophysics Data System (ADS)

It has long been known that, in small catchments, stream water discharge and chemistry are highly variable but the variability decreases gradually with an increase in the catchment area. Wood et al. (1988) showed that model calculations of infiltration and the runoff rate became constant above a certain threshold area. They defined the threshold area as the representative elementary area (REA) and stated that above the REA only minimum knowledge of the underlying parameters is needed to explain the stream water discharge and chemistry. Subsequently, empirical studies were conducted in several catchments. These studies all verified the existence of an REA in real catchments and indicated that the REA values differed among catchments. The results also suggested that the confluence processes of stream water discharge and chemistry differed among catchments. However, it has not been clarified how the confluence processes behave and why processes differ among catchments. One of the unclear things to resolve is whether the variability of discharge and chemistry among small catchments can be regarded as randomness or if it is organized. Two previous studies examined it and reported the opposite results. Woods et al. (1995) reported that organization was apparent from their observations of specific discharge. However, Asano and Uchida (2010) stated that their results for SiO2 could be regarded as randomness. These studies targeted different observed items and different catchments. Therefore, general knowledge about organization of stream water discharge and chemistry has not been obtained. We observed spatial variability of stream water discharge and chemistry and examined the existence of spatial organization by using the statistical method. Our objective was to elucidate whether the spatial organization exists about stream water discharge and chemistry. Observations were conducted in three forested catchments in Japan. Snapshot samplings of stream water discharge and chemistry were conducted at low flow conditions. We compared observed data with the theoretical line suggested by Woods et al. (1995). Our results showed that the spatial variability in observed items did not completely decrease along the theoretical line in any catchment. Furthermore, the results for dissolved matter were different from the results for specific discharge. Specific discharge showed higher average values in small catchments than in the entire catchment, and convergence of specific discharge occurred more quickly than did convergence of dissolved components. These results meant that the variability and convergence of stream water discharge and chemistry couldn't be regarded as simple mixing of randomly distributed variability and verified the existence of organization. We discussed the factor of forming the spatial organization by using conceptual model considering micro topography.

Egusa, T.; Ohte, N.; Oda, T.; Suzuki, M.

2013-12-01

257

Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 4, Organic methods  

SciTech Connect

This interim notice covers the following: extractable organic halides in solids, total organic halides, analysis by gas chromatography/Fourier transform-infrared spectroscopy, hexadecane extracts for volatile organic compounds, GC/MS analysis of VOCs, GC/MS analysis of methanol extracts of cryogenic vapor samples, screening of semivolatile organic extracts, GPC cleanup for semivolatiles, sample preparation for GC/MS for semi-VOCs, analysis for pesticides/PCBs by GC with electron capture detection, sample preparation for pesticides/PCBs in water and soil sediment, report preparation, Florisil column cleanup for pesticide/PCBs, silica gel and acid-base partition cleanup of samples for semi-VOCs, concentrate acid wash cleanup, carbon determination in solids using Coulometrics` CO{sub 2} coulometer, determination of total carbon/total organic carbon/total inorganic carbon in radioactive liquids/soils/sludges by hot persulfate method, analysis of solids for carbonates using Coulometrics` Model 5011 coulometer, and soxhlet extraction.

Not Available

1993-08-01

258

ORGANIC CHEMISTRY I Instructor: Professor Hyun-Soon Chong Chemistry Division, BCPS Dept, IIT, LS 398,  

E-print Network

molecules. Understand the stereochemistry of organic molecules. 5. Demonstrate proficiency in acid base chemical reactions leading to or involving alkanes, alkyl halides, alkenes, alkynes, alcohols and related substances. 3. Draw structures of products of organic chemical reactions involving alkanes, alkyl halides

Heller, Barbara

259

Occupational health experience with organic additives  

SciTech Connect

For many decades, interest in occupational medicine has been focused on the wide variety of organic additives, which includes a large number of substances, for example, dyestuffs, pigments, and auxiliaries for the textile, leather, and paper industries. The reason is that, if the recommended precautions are not observed, there is a risk of exposure to most of these substances during both production and use. Moreover, over the years, some additives have caused concern and aroused suspicion regarding adverse effects on health. In order to deal with health problems in this field, it is important to be aware of how, what, and where occupational diseases or accidents arise. Much knowledge has been gained about these, and it would be an impossible task to give a systematic survey of the data that have accumulated, especially since it is necessary to take account of the problem of exposure to more than one substance. Thus an attempt is made to report on occupational health experience in general, and to demonstrate how an industrial hygienist may approach the many and various problems. Some epidemiological studies on organic additives (auramine, anthraquinone dyestuffs, organic dyes, etc.) are discussed.

Thiess, A.M.; Wellenreuther, G.

1984-12-01

260

Approved Module Information for CH3103, 2014/5 Module Title/Name: Organic Chemistry III Module Code: CH3103  

E-print Network

. These rapidly evolving areas of chemistry are especially relevant to the pharmaceutical industry but are also Lectures [Part 1] Combinatorial chemistry and its relevance to the pharmaceutical industry ConceptsApproved Module Information for CH3103, 2014/5 Module Title/Name: Organic Chemistry III Module Code

Neirotti, Juan Pablo

261

Filtrates and Residues: Saturated and Unsaturated Fats: An Organic Chemistry Demonstration.  

ERIC Educational Resources Information Center

Background information and procedures are provided for an experiment in which an oxidation reaction is used to distinguish saturated from unsaturated fats. Results of the experiment lead to discussions and investigations of such areas as digestion chemistry, enzymes, hydrogenation, and the relationship between heart disease and fat consumption.…

Broniec, Rick

1985-01-01

262

Touring the Tomato: A Suite of Chemistry Laboratory Experiments.  

PubMed

An eight-session interdisciplinary laboratory curriculum has been designed using a suite of analytical chemistry techniques to study biomaterials derived from an inexpensive source such as the tomato fruit. A logical progression of research-inspired laboratory modules serves to "tour" the macroscopic characteristics of the fruit and the submicroscopic properties of its constituent cuticular biopolymers by atomic force microscopy (AFM), UV-visible, and nuclear magnetic resonance (NMR) methods at increasingly detailed molecular levels. The modular curriculum can be tailored for specialty undergraduate courses or summer high school workshops. By applying analytical tools to investigate biopolymers, making connections between molecular and microscale structure, and linking both structural regimes to the functional properties of natural polymers, groundwork is established for further student investigations at the interface of chemistry with biology or chemical engineering. PMID:23526490

Sarkar, Sayantani; Chatterjee, Subhasish; Medina, Nancy; Stark, Ruth E

2013-03-12

263

An Experimental Introduction to Organic Chemistry by Way of Ethene  

ERIC Educational Resources Information Center

Discusses the importance of ethene (ethylene) in industry and the pipeline grid in western Europe for transporting ethene. Describes methods for investigating organic compounds in school laboratories using ethene as the key compound. (JR)

Schmidt, Hans-Jurgen

1973-01-01

264

Chemistry and Applications of Metal-Organic Materials  

E-print Network

control. The postsynthetic modification via click reaction with azide-terminated polyethylene glycol turned them into metallomicelles, which showed controlled release of an anticancer drug 5-fluorouracil. In summary, two kinds of metal-organic materials...

Zhao, Dan

2012-02-14

265

Development of gas-phase chemistry, secondary organic aerosol, and aqueous-phase chemistry modules for PM modeling. Final report  

SciTech Connect

The Coordinating Research Council (CRC) is sponsoring a multi-phase study to develop improved air quality models for particulate matter (PM). Improved urban and regional scale PM air quality models are needed to develop reliable emission control strategies for areas that exceed the National Ambient Air Quality Standards (NAAQS) for PM-2.5 and PM-10, and for National Parks and other Class 1 areas with impaired visibility. This report describes the development and implementation of two process modules for PM models. These particular process modules are needed to simulate secondary aerosol species, which are often the dominate portion of PM-2.5 mass. The first module simulates the gas-phase atmospheric chemistry of the VOC/NO{sub x}/SO{sub 2}/ozone system and the formation of secondary organic aerosols. The module also simulates the formation of inorganic species, including sulfuric acid and nitric acid, that form important aerosol species: sulfate and nitrate; The second module simulates the aqueous-phase chemistry in fogs and clouds. This chemistry primarily enhances SO{sub 2} oxidation rates and leads to enhanced sulfate aerosol concentrations.

Strader, R.; Gurciullo, C.S.; Pandis, S.N.; Kumar, N.; Lurmann, F.W.

1998-10-30

266

Molecular Mechanism of Acrylamide Neurotoxicity: Lessons Learned from Organic Chemistry  

PubMed Central

Background: Acrylamide (ACR) produces cumulative neurotoxicity in exposed humans and laboratory animals through a direct inhibitory effect on presynaptic function. Objectives: In this review, we delineate how knowledge of chemistry provided an unprecedented understanding of the ACR neurotoxic mechanism. We also show how application of the hard and soft, acids and bases (HSAB) theory led to the recognition that the ?,?-unsaturated carbonyl structure of ACR is a soft electrophile that preferentially forms covalent bonds with soft nucleophiles. Methods: In vivo proteomic and in chemico studies demonstrated that ACR formed covalent adducts with highly nucleophilic cysteine thiolate groups located within active sites of presynaptic proteins. Additional research showed that resulting protein inactivation disrupted nerve terminal processes and impaired neurotransmission. Discussion: ACR is a type-2 alkene, a chemical class that includes structurally related electrophilic environmental pollutants (e.g., acrolein) and endogenous mediators of cellular oxidative stress (e.g., 4-hydroxy-2-nonenal). Members of this chemical family produce toxicity via a common molecular mechanism. Although individual environmental concentrations might not be toxicologically relevant, exposure to an ambient mixture of type-2 alkene pollutants could pose a significant risk to human health. Furthermore, environmentally derived type-2 alkenes might act synergistically with endogenously generated unsaturated aldehydes to amplify cellular damage and thereby accelerate human disease/injury processes that involve oxidative stress. Conclusions: These possibilities have substantial implications for environmental risk assessment and were realized through an understanding of ACR adduct chemistry. The approach delineated here can be broadly applied because many toxicants of different chemical classes are electrophiles that produce toxicity by interacting with cellular proteins. PMID:23060388

Gavin, Terrence

2012-01-01

267

310 Toxicological Chemistry The fundamentals of organic chemistry are reviewed in Chapter 1. The present  

E-print Network

of the organic compounds. Hydrocarbons occur naturally in petroleum, natural gas, and tar sands and they can combustion in an oxygen-deficient atmosphere or in an automobile engine, in which significant quantities

Ma, Lena

268

Organic nitrogen chemistry during low-grade metamorphism  

USGS Publications Warehouse

Most of the organic nitrogen (Norg) on Earth is disseminated in crustal sediments and rocks in the form of fossil nitrogen-containing organic matter. The chemical speciation of fossil Norg within the overall molecular structure of organic matter changes with time and heating during burial. Progressive thermal evolution of organic matter involves phases of enhanced elimination of Norg and ultimately produces graphite containing only traces of nitrogen. Long-term chemical and thermal instability makes the chemical speciation of Norg a valuable tracer to constrain the history of sub-surface metamorphism and to shed light on the subsurface biogeochemical nitrogen cycle and its participating organic and inorganic nitrogen pools. This study documents the evolutionary path of Norg speciation, transformation and elimination before and during metamorphism and advocates the use of X-ray photoelectron spectroscopy (XPS) to monitor changes in Norg speciation as a diagnostic tool for organic metamorphism. Our multidisciplinary evidence from XPS, stable isotopes, traditional quantitative coal analyses, and other analytical approaches shows that at the metamorphic onset Norg is dominantly present as pyrrolic and pyridinic nitrogen. The relative abundance of nitrogen substituting for carbon in condensed, partially aromatic systems (where N is covalently bonded to three C atoms) increases exponentially with increasing metamorphic grade, at the expense of pyridinic and pyrrolic nitrogen. At the same time, much Norg is eliminated without significant nitrogen isotope fractionation. The apparent absence of Rayleigh-type nitrogen isotopic fractionation suggests that direct thermal loss of nitrogen from an organic matrix does not serve as a major pathway for Norg elimination. Instead, we propose that hot H, O-containing fluids or some of their components gradually penetrate into the carbonaceous matrix and eliminate Norg along a progressing reaction front, without causing nitrogen isotope fractionation in the residual Norg in the unreacted core of the carbonaceous matrix. Before the reaction front can reach the core, an increasing part of core Norg chemically stabilizes in the form of nitrogen atoms substituting for carbon in condensed, partially aromatic systems forming graphite-like structural domains with delocalized ??-electron systems (nitrogen atoms substituting for "graphitic" carbon in natural metamorphic organic matter). Thus, this nitrogen species with a conservative isotopic composition is the dominant form of residual nitrogen at higher metamorphic grade. ?? 2007 Elsevier Ltd. All rights reserved.

Boudou, J.-P.; Schimmelmann, A.; Ader, M.; Mastalerz, Maria; Sebilo, M.; Gengembre, L.

2008-01-01

269

Supramolecular chemistry: from molecular information towards self-organization and complex matter  

NASA Astrophysics Data System (ADS)

Molecular chemistry has developed a wide range of very powerful procedures for constructing ever more sophisticated molecules from atoms linked by covalent bonds. Beyond molecular chemistry lies supramolecular chemistry, which aims at developing highly complex chemical systems from components interacting via non-covalent intermolecular forces. By the appropriate manipulation of these interactions, supramolecular chemistry became progressively the chemistry of molecular information, involving the storage of information at the molecular level, in the structural features, and its retrieval, transfer, and processing at the supramolecular level, through molecular recognition processes operating via specific interactional algorithms. This has paved the way towards apprehending chemistry also as an information science. Numerous receptors capable of recognizing, i.e. selectively binding, specific substrates have been developed, based on the molecular information stored in the interacting species. Suitably functionalized receptors may perform supramolecular catalysis and selective transport processes. In combination with polymolecular organization, recognition opens ways towards the design of molecular and supramolecular devices based on functional (photoactive, electroactive, ionoactive, etc) components. A step beyond preorganization consists in the design of systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined supramolecular architectures by self-assembly from their components. Self-organization processes, directed by the molecular information stored in the components and read out at the supramolecular level through specific interactions, represent the operation of programmed chemical systems. They have been implemented for the generation of a variety of discrete functional architectures of either organic or inorganic nature. Self-organization processes also give access to advanced supramolecular materials, such as supramolecular polymers and liquid crystals, and provide an original approach to nanoscience and nanotechnology. In particular, the spontaneous but controlled generation of well-defined, functional supramolecular architectures of nanometric size through self-organization represents a means of performing programmed engineering and processing of nanomaterials. Supramolecular chemistry is intrinsically a dynamic chemistry, in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their constituents. The same holds for molecular chemistry when a molecular entity contains covalent bonds that may form and break reversibly, so as to make possible a continuous change in constitution and structure by reorganization and exchange of building blocks. This behaviour defines a constitutional dynamic chemistry that allows self-organization by selection as well as by design at both the molecular and supramolecular levels. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization by selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation in a Darwinistic fashion. The merging of the features, information and programmability, dynamics and reversibility, constitution and structural diversity, points towards the emergence of adaptative and evolutionary chemistry. Together with the corresponding fields of physics and biology, it constitutes a science of informed matter, of organized, adaptative complex matter. This article was originally published in 2003 by the Israel Academy of Sciences and Humanities in the framework of its Albert Einstein Memorial Lectures series. Reprinted by permission of the Israel Academy of Sciences and Humanities.

Lehn, Jean-Marie

2004-03-01

270

Real World of Industrial Chemistry: Organic Chemicals from Carbon Monoxide.  

ERIC Educational Resources Information Center

Carbon Monoxide obtained from coal may serve as the source for a wide variety of organic compounds. Several of these compounds are discussed, including phosgene, benzaldehyde, methanol, formic acid and its derivatives, oxo aldehydes, acrylic acids, and others. Commercial reactions of carbon monoxide are highlighted in a table. (JN)

Kolb, Kenneth E.; Kolb, Doris

1983-01-01

271

OCCURRENCE & CHEMISTRY OF ORGANIC COMPOUNDS IN HANFORD SITE WASTE TANKS  

Microsoft Academic Search

Volatile and semivolatile organic compounds continuously evolve from the waste tanks at the Hanford Site. Some are identical to the compounds originally transferred to tanks and others are formed through interdependent chemical and radiolytic reactions. This document provides a technical basis for understanding the chemical consequences of long term storage, sluicing, the addition of chemicals, and the prediction of other

L. M. STOCK; J. E. MEACHAM

2004-01-01

272

Size Exclusion Chromatography: An Experiment for High School and Community College Chemistry and Biotechnology Laboratory Programs  

ERIC Educational Resources Information Center

A simple multiday laboratory exercise suitable for use in a high school or community college chemistry course or a biotechnology advanced placement biology course is described. In this experiment students gain experience in the use of column chromatography as a tool for the separation and characterization of biomolecules, thus expanding their…

Brunauer, Linda S.; Davis, Kathryn K.

2008-01-01

273

Lysozyme Thermal Denaturation and Self-Interaction: Four Integrated Thermodynamic Experiments for the Physical Chemistry Laboratory  

ERIC Educational Resources Information Center

As part of an effort to infuse our physical chemistry laboratory with biologically relevant, investigative experiments, we detail four integrated thermodynamic experiments that characterize the denaturation (or unfolding) and self-interaction of hen egg white lysozyme as a function of pH and ionic strength. Students first use Protein Explorer to…

Schwinefus, Jeffrey J.; Schaefle, Nathaniel J.; Muth, Gregory W.; Miessler, Gary L.; Clark, Christopher A.

2008-01-01

274

Thermodynamic Exploration of Eosin-Lysozyme Binding: A Physical Chemistry and Biochemistry Laboratory Experiment  

ERIC Educational Resources Information Center

We developed a modular pair of experiments for use in the undergraduate physical chemistry and biochemistry laboratories. Both experiments examine the thermodynamics of the binding of a small molecule, eosin Y, to the protein lysozyme. The assay for binding is the quenching of lysozyme fluorescence by eosin through resonant energy transfer. In…

Huisman, Andrew J.; Hartsell, Lydia R.; Krueger, Brent P.; Pikaart, Michael J.

2010-01-01

275

GC-MS Analysis of [gamma]-Hydroxybutyric Acid Analogs: A Forensic Chemistry Experiment  

ERIC Educational Resources Information Center

An upper-division forensic chemistry experiment is described. It involves using glycolic acid and sodium glycolate as analogs of [gamma]-hydroxybutyric acid and its sodium salt. The experiment shows the use of silylation in GC-MS analysis and gives students the opportunity to work with a commonly used silylating reagent,…

Henck, Colin; Nally, Luke

2007-01-01

276

Linear Dichroism of Cyanine Dyes in Stretched Polyvinyl Alcohol Films: A Physical Chemistry Laboratory Experiment.  

ERIC Educational Resources Information Center

Provides background information, procedures, and results of an undergraduate physical chemistry experiment on the polarization of absorption spectra of cyanine dyes in stretched polyvinyl alcohol films. The experiment gives a simple demonstration of the concept of linear dichromism and the validity of the TEM method used in the analyses. (JN)

Natarajan, L. V.; And Others

1983-01-01

277

An Enzymatic Clinical Chemistry Laboratory Experiment Incorporating an Introduction to Mathematical Method Comparison Techniques  

ERIC Educational Resources Information Center

An enzymatic laboratory experiment based on the analysis of serum is described that is suitable for students of clinical chemistry. The experiment incorporates an introduction to mathematical method-comparison techniques in which three different clinical glucose analysis methods are compared using linear regression and Bland-Altman difference…

Duxbury, Mark

2004-01-01

278

Annotated List of Chemistry Laboratory Experiments with Computer Access. Final Report.  

ERIC Educational Resources Information Center

Project Chemlab was designed to prepare an "Annotated List of Laboratory Experiments in Chemistry from the Journal of Chemical Education (1957-1979)" and to develop a computer file and program to search for specific types of experiments. Provided in this document are listings (photoreduced copies of printouts) of over 1500 entries classified into…

Bunce, S. C.; And Others

279

Connecting Solubility, Equilibrium, and Periodicity in a Green, Inquiry Experiment for the General Chemistry Laboratory  

ERIC Educational Resources Information Center

We present a novel first-year chemistry laboratory experiment that connects solubility, equilibrium, and chemical periodicity concepts. It employs a unique format that asks students to replicate experiments described in different sample lab reports, each lacking some essential information, rather than follow a scripted procedure. This structure is…

Cacciatore, Kristen L.; Amado, Jose; Evans, Jason J.; Sevian, Hannah

2008-01-01

280

Thai Undergraduate Chemistry Practical Learning Experiences Using the Jigsaw IV Method  

ERIC Educational Resources Information Center

The research reported in this study consisted of an investigation of student learning experiences in Thai chemistry laboratories using the Jigsaw IV method. A hands-on experiment based on the Jigsaw IV method using a real life example based on green tea beverage was designed to improve student affective variables for studying topics related to…

Jansoon, Ninna; Somsook, Ekasith; Coll, Richard K.

2008-01-01

281

Enquiry-Based Learning: Experiences of First Year Chemistry Students Learning Spectroscopy  

ERIC Educational Resources Information Center

We explored the experiences of first year chemistry students of an Enquiry-Based Learning (EBL) approach to learning spectroscopy. An investigation of how students' perceived confidences changed as a result of their experience of using EBL in the spectroscopy course was carried out. Changes in the students' perceived confidence, both in their…

Lucas, Timothy; Rowley, Natalie M.

2011-01-01

282

Incorporating Chemical Information Instruction and Environmental Science into the First-Year Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

The chemical information instruction and environmental science which is incorporated into a first-year organic chemistry laboratory is presented. The students are charged with devised search strategies, conducting online searches and limiting the project scope to ocean systems. The laboratory serves to provide for search strategy development…

Landolt, R. G.

2006-01-01

283

Results Sections in Sociology and Organic Chemistry Articles: A Genre Analysis  

ERIC Educational Resources Information Center

This paper reports a genre study of the Results sections of two samples of 20 research-reporting articles from two disciplines: sociology and organic chemistry. Following the proposal of Bhatia (2004) that genre knowledge needs to be investigated from two perspectives, an "ethnographic perspective" and a "textual perspective," the Results sections…

Bruce, Ian

2009-01-01

284

Grade/Study-Performance Contracts, Enhanced Communication, Cooperative Learning, and Student Performance in Undergraduate Organic Chemistry.  

ERIC Educational Resources Information Center

Describes and evaluates a teaching strategy, designed to increase student retention while maintaining academic performance levels in undergraduate organic chemistry, that uses grade/study-performance contracts, enhanced communication using electronic mail, and cooperative learning. Concludes that a series of interventions can substantially…

Dougherty, Ralph C.

1997-01-01

285

Reasonable Reasoning: Multi-Variate Problem-Solving in Organic Chemistry  

ERIC Educational Resources Information Center

In order to understand how students approach multi-variate problems, we report a study on the cues organic chemistry graduate students perceive from mechanism tasks, and the reasoning processes induced by those cues. We used the think-aloud protocol in interviews with sixteen graduate students as they worked on two types of tasks: one, in which…

Kraft, Adam; Strickland, Amanda M.; Bhattacharyya, Gautam

2010-01-01

286

Microwave-Assisted Chemistry: Synthetic Applications for Rapid Assembly of Nanomaterials and Organics  

EPA Science Inventory

The magic of microwave (MW) heating technique, termed as the Bunsen burner of the 21th Century, has emerged as valuable alternative in synthesis of organics, polymers, inorganics, and nanomaterials. Important innovations in MW-assisted chemistry now enable chemists to prepare cat...

287

Newman Projection Practice 1 Organic Chemistry I Jasperse Newman Projection Practice  

E-print Network

Newman Projection Practice 1 Organic Chemistry I ­ Jasperse Newman Projection Practice A. For each of the following, draw the best and worst Newman projection, relative to the bond indicated. 1. Et Et Cl iPr Et Et iPr Et Et (See page 4 for some summary of operations/steps for handling Newman

Jasperse, Craig P.

288

Using Biocatalysis to Integrate Organic Chemistry into a Molecular Biology Laboratory Course  

ERIC Educational Resources Information Center

Current cutting-edge biomedical investigation requires that the researcher have an operational understanding of several diverse disciplines. Biocatalysis is a field of science that operates at the crossroads of organic chemistry, biochemistry, microbiology, and molecular biology, and provides an excellent model for interdisciplinary research. We…

Beers, Mande; Archer, Crystal; Feske, Brent D.; Mateer, Scott C.

2012-01-01

289

Stereoscopic Projection in Organic Chemistry: Bridging the Gap between Two and Three Dimensions.  

ERIC Educational Resources Information Center

Shows how to make stereo slides of three-dimensional molecular models. The slides have been used to teach chirality, conformational isomerism, how models and two-dimensional representations embody selected aspects of structure, and fundamentals of using the specific model set required in a particular organic chemistry course. (JN)

Rozzelle, Arlene A.; Rosenfeld, Stuart M.

1985-01-01

290

Kinetic versus Static Visuals for Facilitating College Students' Understanding of Organic Reaction Mechanisms in Chemistry  

ERIC Educational Resources Information Center

Using animated computer-generated graphics to assist instruction has recently attracted the attention of educators and educational researchers. The specific focus of this study is to compare the influence of animated visuals with static visuals on college students' understanding of organic reaction mechanisms in chemistry. This study also focuses…

Aldahmash, Abdulwali H.; Abraham, Michael R.

2009-01-01

291

Emissions of volatile organic compounds from vegetation and the implications for atmospheric chemistry  

Microsoft Academic Search

Vegetation provides a major source of reactive carbon entering the atmosphere. These compounds play an important role in (1) shaping global tropospheric chemistry, (2) regional photochemical oxidant formation, (3) balancing the global carbon cycle, and (4) production of organic acids which contribute to acidic deposition in rural areas. Present estimates place the total annual global emission of these compounds between

Fred Fehsenfeld; Jack Calvert; Ray Fall; Paul Goldan; A. B. Guenther; C. N. Hewitt; Brian Lamb; Shaw Liu; Michael Trainer; Hal Westberg; Pat Zimmerman

1992-01-01

292

A Survey of the Practices, Procedures, and Techniques in Undergraduate Organic Chemistry Teaching Laboratories  

ERIC Educational Resources Information Center

A survey was conducted of four-year institutions that teach undergraduate organic chemistry laboratories in the United States. The data include results from over 130 schools, describes the current practices at these institutions, and discusses the statistical results such as the scale of the laboratories performed, the chemical techniques applied,…

Martin, Christopher B.; Schmidt, Monica; Soniat, Michael

2011-01-01

293

Implementation of a Peer-Led Team Learning Instructional Approach in an Undergraduate Organic Chemistry Course.  

ERIC Educational Resources Information Center

Focuses on the implementation of a peer-led team learning (PLTL) instructional approach for students in an undergraduate organic chemistry course and the evaluation of student outcomes over eight years. Compares students who experienced the student-centered instruction and worked in small groups facilitated by a peer leader to students who…

Tien, Lydia T.; Roth, Vicki; Kampmeier, J. A.

2002-01-01

294

An Introductory Organic Chemistry Review Homework Exercise: Deriving Potential Mechanisms for Glucose Ring Opening in Mutarotation  

ERIC Educational Resources Information Center

A unique homework assignment has been designed as a review exercise to be implemented near the end of the one-year undergraduate organic chemistry sequence. Within the framework of the exercise, students derive potential mechanisms for glucose ring opening in the aqueous mutarotation process. In this endeavor, 21 general review principles are…

Murdock, Margaret; Holman, R. W.; Slade, Tyler; Clark, Shelley L. D.; Rodnick, Kenneth J.

2014-01-01

295

Adapting to Student Learning Styles: Engaging Students with Cell Phone Technology in Organic Chemistry Instruction  

ERIC Educational Resources Information Center

Students of organic chemistry traditionally make 3 x 5 in. flash cards to assist learning nomenclature, structures, and reactions. Advances in educational technology have enabled flash cards to be viewed on computers, offering an endless array of drilling and feedback for students. The current generation of students is less inclined to use…

Pursell, David P.

2009-01-01

296

Evaluation of Student Learning in Organic Chemistry Using the SOLO Taxonomy.  

ERIC Educational Resources Information Center

Describes the use of a standardized instrument, the Structure of Observed Learning Outcomes (SOLO) taxonomy, in an organic chemistry course at a small liberal arts college for women. Concludes that the method is a powerful tool for analyzing points of difficulty in student learning and following student progress in the understanding of particular…

Hodges, Linda C.; Harvey, Lilia C.

2003-01-01

297

2005 Nobel Prize in Chemistry: Development of the Olefin Metathesis Method in Organic Synthesis  

ERIC Educational Resources Information Center

The 2005 Nobel Prize in Chemistry was awarded "for the development of the metathesis method in organic synthesis". The discoveries of the laureates provided a chemical reaction used daily in the chemical industry for the efficient and more environmentally friendly production of important pharmaceuticals, fuels, synthetic fibers, and many other…

Casey, Charles P.

2006-01-01

298

The Use of Solid Aluminum Heat Transfer Devices in Organic Chemistry Laboratory Instruction and Research.  

ERIC Educational Resources Information Center

Presents a practical and attractive alternative to the sand bath used in the microscale procedures developed by Mayo, Pike, and Butcher. Urges the organic chemistry teaching community to continue towards complete conversion to microscale techniques. Presents the use of aluminum devices in the microlaboratory. (MVL)

Lodwig, Siegfried N.

1989-01-01

299

Case Study Using Online Homework in Undergraduate Organic Chemistry: Results and Student Attitudes  

ERIC Educational Resources Information Center

Managing student needs for effective learning in a large-enrollment, introductory organic chemistry course can be a challenging task. Because instructor time is at a premium, it is imperative to find resources that engage the students in active learning and provide them with feedback about their understanding of course content. Appropriately…

Parker, Laurie L.; Loudon, G. Marc

2013-01-01

300

Solvent-free microwave organic synthesis as an efficient procedure for green chemistry  

Microsoft Academic Search

Solvent-free methods are especially adapted to organic synthesis under Green Chemistry conditions. When coupled to microwave (MW) irradiation, it results in very efficient and clean procedures with noticeable improvements over classical methods. To take advantage of MW specific effects, the most suitable cases involve reactions with polar mechanisms with increase of the polarity during the progress of the reaction and

André Loupy

2004-01-01

301

Assessment of Organic Chemistry Students' Knowledge of Resonance-Related Structures  

ERIC Educational Resources Information Center

This study examines how well second-year nonmajor organic chemistry students are learning to draw, interpret, and understand resonance-related structures. Students were tested seven times throughout an academic year using a set of four tasks that reflected their understanding of what these structures represent and how they relate to each other.…

Betancourt-Perez, Rosa; Olivera, Luis Javier; Rodriguez, Julio E.

2010-01-01

302

Chem 342 Jasperse Syllabus 1 ORGANIC CHEMISTRY II: CHEMISTRY 342 SYLLABUS  

E-print Network

practice and sometimes tips, and will help to keep you from procrastinating. Test Schedule Test 1 Wednesday letter grades Tests 1-4 350 points A 90% Take-Home Quizzes 20 points B 80% Online homework 70 points Practice Tests Organic I Review Textbook Info Miscellanious Take-Home "Quizzes: http

Jasperse, Craig P.

303

Interactions between Carbon and Nitrogen Mineralization and Soil Organic Matter Chemistry in Arctic Tundra Soils  

Microsoft Academic Search

We used long-term laboratory incubations and chemical fractionation to characterize the mineralization dynamics of organic\\u000a soils from tussock, shrub, and wet meadow tundra communities, to determine the relationship between soil organic matter (SOM)\\u000a decomposition and chemistry, and to quantify the relative proportions of carbon (C) and nitrogen (N) in tundra SOM that are\\u000a biologically available for decomposition. In all soils

Michael N. Weintraub; Joshua P. Schimel

2003-01-01

304

Send Orders of Reprints at reprints@benthamscience.net 126 Letters in Organic Chemistry, 2013, 10, 126-130  

E-print Network

Send Orders of Reprints at reprints@benthamscience.net 126 Letters in Organic Chemistry, 2013, 10 The development of microwave ovens for the heating of food has more than 60-year old history [1] and since the first application of microwave heating in organic chemistry (Ge- dye et al., 1986) [2] the number

Cirkva, Vladimir

305

Tholins - Organic chemistry of interstellar grains and gas  

Microsoft Academic Search

The paper discusses tholins, defined as complex organic solids formed by the interaction of energy - for example, UV light or spark discharge - with various mixtures of cosmically abundant gases - CH4, C2H6, NH3, H2O, HCHO, and H2S. It is suggested that tholins occur in the interstellar medium and are responsible for some of the properties of the interstellar

Carl Sagan; B. N. Khare

1979-01-01

306

Shock-induced chemistry in simple organic molecules  

NASA Astrophysics Data System (ADS)

Interrogating chemical reactions behind a shock front is immensely difficult, and as a result, the details of shock-induced chemistry remain poorly understood. Shock compression creates transient distorted structures from which molecular reactions initiate. Previous works have reported that dimerizations, polymerizations, ring-opening and decomposition reactions occur under shock compression, depending on molecular structure. Certainly for explosives, exothermic decomposition reactions ultimately drive self-supported detonation. Questions regarding the thresholds for incipient reaction for different chemical functional groups, the nature of first and subsequent reaction steps, and the influence of shock input conditions on reaction kinetics remain to be answered. Evidence of reaction can be discerned from discontinuities in the mechanical variables for reactions with a change in density along the reaction coordinate, similar to first-order phase transformations. Here, we have applied in-situ electromagnetic gauging at multiple Lagrangian positions to elucidate the evolution of multiple-wave structures associated with shock-induced reactions. We have applied in-situ gauging, in concert with reactive molecular dynamic simulations, to investigate shock-reactivity of several simple functional groups: carbon-carbon double (-C=C-) and triple bonds, and nitriles (e.g. phenylacetylene and acrylonitrile), and aromatic ring structures (benzene), all building blocks for explosives. From measurements of the reactive flow, we have obtained detailed information about the temporal evolution of the waves, and global kinetics associated with transformation(s) between partially- and fully-reacted states. Near the reactive threshold, evolution in particle velocities point to reaction timescales on the order of several hundred nanoseconds. We have defined the reactive cusp Hugoniot states, and established the relative order of group reactivity under single shock conditions. These observations will be compared with reactions from the solid phase under static high pressure/temperature conditions, with a description of crystalline phase, and identification of polymerized products by in-situ x-ray diffraction and spectroscopic methods.

Dattelbaum, Dana

2011-06-01

307

Computer Programs for Chemistry Experiments I and II.  

ERIC Educational Resources Information Center

This unit of instruction includes nine laboratory experiments. All of the experiments are from the D.C. Health Revision of the Chemical Education Materials Study (CHEMS) with one exception. Program six is the lab from the original version of the CHEMS program. Each program consists of three parts (1) the lab and computer hints, (2) the description…

Reynard, Dale C.

308

Nobel Prize in Chemistry. Development of the Olefin Metathesis Method in Organic Synthesis  

NASA Astrophysics Data System (ADS)

The 2005 Nobel Prize in Chemistry was awarded to Yves Chauvin of the Institut Français du Pétrole, Robert H. Grubbs of CalTech, and Richard R. Schrock of MIT "for development of the metathesis method in organic synthesis". The discoveries of the laureates provided a chemical reaction now used daily in the chemical industry for the efficient and more environmentally friendly production of important pharmaceuticals, fuels, synthetic fibers, and many other products. This article tells the story of how olefin metathesis became a truly useful synthetic transformation and a triumph for mechanistic chemistry, and illustrates the importance of fundamental research. See JCE Featured Molecules .

Casey, Charles P.

2006-02-01

309

Demystifying the Chemistry Literature: Building Information Literacy in First-Year Chemistry Students through Student-Centered Learning and Experiment Design  

ERIC Educational Resources Information Center

This paper describes curriculum modules developed for first-year general chemistry laboratory courses that use scientific literature and creative experiment design to build information literacy in a student-centered learning environment. Two curriculum units are discussed: Exploring Scientific Literature and Design Your Own General Chemistry

Bruehl, Margaret; Pan, Denise; Ferrer-Vinent, Ignacio J.

2015-01-01

310

Discovering Factors that Influence the Decision to Pursue a Chemistry-Related Career: A Comparative Analysis of the Experiences of Non Scientist Adults and Chemistry Teachers in Greece  

ERIC Educational Resources Information Center

This study aims at identifying factors that influence students' choice not to pursue a chemistry-related career by analyzing the experiences of secondary education chemistry teachers in Greece and of Greek adults who have not pursued studies related to science. Data collection was done with the method of individual structured interviews. The…

Salta, Katerina; Gekos, Michael; Petsimeri, Irene; Koulougliotis, Dionysios

2012-01-01

311

Annotated List of Laboratory Experiments in Chemistry from the Journal of Chemical Education. Second Edition, 1957-1984.  

ERIC Educational Resources Information Center

This document is the second edition of the Annotated List of Laboratory Experiments in Chemistry first published in 1980. All entries in the Journal of Chemical Education describing laboratory experiments in chemistry or laboratory descriptions suitable for student experiments or projects, for the years 1957-1984 inclusive, have been listed and…

Allen, C. B.; And Others

312

Green, Enzymatic Syntheses of Divanillin and Diapocynin for the Organic, Biochemistry, or Advanced General Chemistry Laboratory  

ERIC Educational Resources Information Center

Environmentally benign chemistry is an increasingly important topic both in the classroom and the laboratory. In this experiment, students synthesize divanillin from vanillin or diapocynin from apocynin, using horseradish peroxidase and hydrogen peroxide in water. The dimerized products form rapidly at ambient temperature and are isolated by…

Nishimura, Rachel T.; Giammanco, Chiara H.; Vosburg, David A.

2010-01-01

313

Diels-Alder Cycloadditions: A MORE Experiment in the Organic Laboratory Including a Diene Identification Exercise Involving NMR Spectroscopy and Molecular Modeling  

ERIC Educational Resources Information Center

Two Diels-Alder reactions are described that are suitable for a MORE (microwave-induced organic reaction enhanced) experiment in the organic chemistry laboratory course. A second experiment in which the splitting patterns of the vinyl protons in the nuclear magnetic resonance (NMR) spectra of two MORE adducts are used in conjunction with molecular…

Shaw, Roosevelt; Severin, Ashika; Balfour, Miguel; Nettles, Columbus

2005-01-01

314

The Kinetics of Photographic Development: A General Chemistry Experiment.  

ERIC Educational Resources Information Center

Student activities and experimental procedures are described for an experiment using black and white photographic development to illustrate the determination of reaction rate, kinetic order of a reactant, and activation energy. (Author/SK)

Byrd, J. E.; Perona, M. J.

1982-01-01

315

50-Minute Experiment: Soil Analysis for High School Chemistry Students.  

ERIC Educational Resources Information Center

Lists equipment and materials needed and procedures for analyzing soil, in which secondary school students experience practical applications to acid-base reactions, pH, oxidation-reduction, precipitation and solubility. (CS)

Baruch, Gerard, Ed.; And Others

1980-01-01

316

Lasers in the Undergraduate Curriculum II: Coursework Experiments and Research Projects.  

ERIC Educational Resources Information Center

Described are 14 experiments that use lasers. Topic areas include physical chemistry, analytical chemistry, organic chemistry, inorganic chemistry, and biochemistry. Instrumentation and the use of the laser in undergraduate research are discussed. (CW)

Steehler, Jack K.

1990-01-01

317

Chemistry Graduate Teaching Assistants' Experiences in Academic Laboratories and Development of a Teaching Self-image  

NASA Astrophysics Data System (ADS)

Graduate teaching assistants (GTAs) play a prominent role in chemistry laboratory instruction at research based universities. They teach almost all undergraduate chemistry laboratory courses. However, their role in laboratory instruction has often been overlooked in educational research. Interest in chemistry GTAs has been placed on training and their perceived expectations, but less attention has been paid to their experiences or their potential benefits from teaching. This work was designed to investigate GTAs' experiences in and benefits from laboratory instructional environments. This dissertation includes three related studies on GTAs' experiences teaching in general chemistry laboratories. Qualitative methods were used for each study. First, phenomenological analysis was used to explore GTAs' experiences in an expository laboratory program. Post-teaching interviews were the primary data source. GTAs experiences were described in three dimensions: doing, knowing, and transferring. Gains available to GTAs revolved around general teaching skills. However, no gains specifically related to scientific development were found in this laboratory format. Case-study methods were used to explore and illustrate ways GTAs develop a GTA self-image---the way they see themselves as instructors. Two general chemistry laboratory programs that represent two very different instructional frameworks were chosen for the context of this study. The first program used a cooperative project-based approach. The second program used weekly, verification-type activities. End of the semester interviews were collected and served as the primary data source. A follow-up case study of a new cohort of GTAs in the cooperative problem-based laboratory was undertaken to investigate changes in GTAs' self-images over the course of one semester. Pre-semester and post-semester interviews served as the primary data source. Findings suggest that GTAs' construction of their self-image is shaped through the interaction of 1) prior experiences, 2) training, 3) beliefs about the nature of knowledge, 4) beliefs about the nature of laboratory work, and 5) involvement in the laboratory setting. Further GTAs' self-images are malleable and susceptible to change through their laboratory teaching experiences. Overall, this dissertation contributes to chemistry education by providing a model useful for exploring GTAs' development of a self-image in laboratory teaching. This work may assist laboratory instructors and coordinators in reconsidering, when applicable, GTA training and support. This work also holds considerable implications for how teaching experiences are conceptualized as part of the chemistry graduate education experience. Findings suggest that appropriate teaching experiences may contribute towards better preparing graduate students for their journey in becoming scientists.

Gatlin, Todd Adam

318

Eliciting Metacognitive Experiences and Reflection in a Year 11 Chemistry Classroom: An Activity Theory Perspective  

NASA Astrophysics Data System (ADS)

Concerns regarding students' learning and reasoning in chemistry classrooms are well documented. Students' reasoning in chemistry should be characterized by conscious consideration of chemical phenomenon from laboratory work at macroscopic, molecular/sub-micro and symbolic levels. Further, students should develop metacognition in relation to such ways of reasoning about chemistry phenomena. Classroom change eliciting metacognitive experiences and metacognitive reflection is necessary to shift entrenched views of teaching and learning in students. In this study, Activity Theory is used as the framework for interpreting changes to the rules/customs and tools of the activity systems of two different classes of students taught by the same teacher, Frances, who was teaching chemical equilibrium to those classes in consecutive years. An interpretive methodology involving multiple data sources was employed. Frances explicitly changed her pedagogy in the second year to direct students attention to increasingly consider chemical phenomena at the molecular/sub-micro level. Additionally, she asked students not to use the textbook until toward the end of the equilibrium unit and sought to engage them in using their prior knowledge of chemistry to understand their observations from experiments. Frances' changed pedagogy elicited metacognitive experiences and reflection in students and challenged them to reconsider their metacognitive beliefs about learning chemistry and how it might be achieved. While teacher change is essential for science education reform, students are not passive players in change efforts and they need to be convinced of the viability of teacher pedagogical change in the context of their goals, intentions, and beliefs.

Thomas, Gregory P.; McRobbie, Campbell J.

2013-06-01

319

Chemical insights, explicit chemistry and yields of secondary organic aerosol from methylglyoxal and glyoxal  

NASA Astrophysics Data System (ADS)

Atmospherically abundant, volatile water soluble organic compounds formed through gas phase chemistry (e.g., glyoxal (C2), methylglyoxal (C3) and acetic acid) have great potential to form secondary organic aerosol (SOA) via aqueous chemistry in clouds, fogs and wet aerosols. This paper (1) provides chemical insights into aqueous-phase OH radical-initiated reactions leading to SOA formation from methylglyoxal and (2) uses this and a previously published glyoxal mechanism (Lim et al., 2010) to provide SOA yields for use in chemical transport models. Detailed reaction mechanisms including peroxy radical chemistry and a full kinetic model for aqueous photochemistry of acetic acid and methylglyoxal are developed and validated by comparing simulations with the experimental results from previous studies (Tan et al., 2010, 2012). This new methylglyoxal model is then combined with the previous glyoxal model (Lim et al., 2010), and is used to simulate the profiles of products and to estimate SOA yields. At cloud relevant concentrations (∼ 10-6-∼ 10-3 M; Munger et al., 1995) of glyoxal and methylglyoxal, the major photooxidation products are oxalic acid and pyruvic acid, and simulated SOA yields (by mass) are ∼ 120% for glyoxal and ∼ 80% for methylglyoxal. Oligomerization of unreacted aldehydes during droplet evaporation could enhance yields. In wet aerosols, where total dissolved organics are present at much higher concentrations (∼ 10 M), the major products are oligomers formed via organic radical-radical reactions, and simulated SOA yields (by mass) are ∼ 90% for both glyoxal and methylglyoxal.

Lim, Y. B.; Tan, Y.; Turpin, B. J.

2013-02-01

320

Booknote: Core Organic Chemistry, 2nd Edition (by Marye Anne Fox and James K. Whitesell)  

NASA Astrophysics Data System (ADS)

Jones and Bartlett: Sudbury, MA, 1997. 928 pp. ISBN 0763703672. 71.25. "This version...answers your request for an organic chemistry text that you can cover completely in a two-semester course." Such is Jones and Bartlett's rationale for omitting the special-topics chapters 17-23 from the second edition of Fox and Whitesell's more ambitious Organic Chemistry text. The 16 chapters that remain as this Core Organic Chemistry text are identical to those in the parent text. The strengths and advantages of the authors' approach to presenting organic chemistry remain, of course (J. Chem. Educ. 1997, 74, 1045-1046). To select a text on the basis of whether most pages can be covered seems a tenuous choice. A more important question is what value to the student is gained or lost by the choice made. Is it of greater value to provide a less voluminous (by 320 pages), less weighty (by about 1.2 pounds), and less expensive (88.75 vs $71.25) book, or to provide the students with the opportunity to read, perhaps on their own initiative, chapters on polymeric materials, naturally occurring oxygen and nitrogen compounds, noncovalent interactions and molecular recognition, molecular recognition of chiral molecules, catalyzed reactions, cofactors for biological reactions, energy storage in organic molecules, and molecular basis for drug action? I would argue that the potential for benefit to the student is better served by having those topics available for perusal, even if not formally presented in the class. It should be noted that arrangements can be made to purchase any of these special topics separately, and integrate them into a course as desired.

Stradling, Samuel S.

1998-11-01

321

Enthalpy of Vaporization by Gas Chromatography: A Physical Chemistry Experiment  

ERIC Educational Resources Information Center

An experiment is conducted to measure the enthalpy of vaporization of volatile compounds like methylene chloride, carbon tetrachloride, and others by using gas chromatography. This physical property was measured using a very tiny quantity of sample revealing that it is possible to measure the enthalpies of two or more compounds at the same time.

Ellison, Herbert R.

2005-01-01

322

Coulometric Analysis Experiment for the Undergraduate Chemistry Laboratory  

ERIC Educational Resources Information Center

An undergraduate experiment on coulometric analysis of four commercial household products is presented. A special type of coulometry cell made of polydimethylsiloxane (PDMS) polymer is utilized. The PDMS cell consists of multiple analyte compartments and an internal network of salt bridges. Experimental procedure for the analysis of the acid in a…

Dabke, Rajeev B.; Gebeyehu, Zewdu; Thor, Ryan

2011-01-01

323

Sampling Error in a Particulate Mixture: An Analytical Chemistry Experiment.  

ERIC Educational Resources Information Center

Presents an undergraduate experiment demonstrating sampling error. Selected as the sampling system is a mixture of potassium hydrogen phthalate and sucrose; using a self-zeroing, automatically refillable buret to minimize titration time of multiple samples and employing a dilute back-titrant to obtain high end-point precision. (CS)

Kratochvil, Byron

1980-01-01

324

Cation Hydration Constants by Proton NMR: A Physical Chemistry Experiment.  

ERIC Educational Resources Information Center

Studies the polarization effect on water by cations and anions. Describes an experiment to illustrate the polarization effect of sodium, lithium, calcium, and strontium ions on the water molecule in the hydration spheres of the ions. Analysis is performed by proton NMR. (MVL)

Smith, Robert L.; And Others

1988-01-01

325

Laser-Induced Molecular Fluorescence: A Physical Chemistry Experiment.  

ERIC Educational Resources Information Center

Describes a companion experiment to the experimental study of the di-iodide visible absorption spectrum. Experimental details, interpretation, and data analysis are provided for an analysis of the di-iodide fluorescence excited by a visible laser, using a Raman instrument. (CS)

Tellinghuisen, Joel

1981-01-01

326

Redox chemistry and natural organic matter (NOM): Geochemists' dream, analytical chemists' nightmare  

USGS Publications Warehouse

Natural organic matter (NOM) is an inherently complex mixture of polyfunctional organic molecules. Because of their universality and chemical reversibility, oxidation/reductions (redox) reactions of NOM have an especially interesting and important role in geochemistry. Variabilities in NOM composition and chemistry make studies of its redox chemistry particularly challenging, and details of NOM-mediated redox reactions are only partially understood. This is in large part due to the analytical difficulties associated with NOM characterization and the wide range of reagents and experimental systems used to study NOM redox reactions. This chapter provides a summary of the ongoing efforts to provide a coherent comprehension of aqueous redox chemistry involving NOM and of techniques for chemical characterization of NOM. It also describes some attempts to confirm the roles of different structural moieties in redox reactions. In addition, we discuss some of the operational parameters used to describe NOM redox capacities and redox states, and describe nomenclature of NOM redox chemistry. Several relatively facile experimental methods applicable to predictions of the NOM redox activity and redox states of NOM samples are discussed, with special attention to the proposed use of fluorescence spectroscopy to predict relevant redox characteristics of NOM samples.

MacAlady, Donald L.; Walton-Day, Katherine

2011-01-01

327

Wet Chemistry on SAM: How it Helps to Detect Organics on Mars  

NASA Astrophysics Data System (ADS)

For the first time in the history of space exploration, a mission of interest to astrobiology could be able to analyze refractory organic compounds in the soil of Mars with wet chemistry. This analytical technique modifies organic components in such a way that improves their detection, either by releasing the compounds from sample matrices, or by changing the chemical structure to be amenable to analytical conditions. The latter effect is particularly important when polar compounds are present. Sample Analysis at Mars (SAM), on the Curiosity rover of the Mars Science Laboratory mission, onboards two wet chemistry experiments: derivatization [1-2] and thermochemolysis [3-4]. Here we report on the nature of the MTBSTFA derivatization experiment in SAM, the detection of MTBSTFA in the first SAM analyzes, and the implications of this detection. Chemical derivatization of polar molecular compounds is achieved by the MTBSTFA (N-Methyl-N-tert-butyldimethylsilyltrifluoroacetamide) / DMF (Dimethylformamide) silylation reaction in order to transform refractory polar compounds into a more volatile form that can be analyzed and detected by GCMS. The first samples of Martian soil (Rocknest, Gale crater) have been analyzed by evolved gas analysis (EGA) and via GC using thermal conductivity (TCD) and MS detection. The samples have been heated up to approximately 840°C with a heating rate of 35°C/min under He flow. The evolved gas was analyzed directly by the QMS in EGA mode. For GC analyses, the majority of the gas released was trapped on a hydrocarbon trap (silica beads, Tenax TA, Carbosieve G) over a specific temperature range. Trapped volatiles were then released by heating the trap to ~300 °C and sent to the GC under He flow. The first results obtained when running an analysis with an empty cup (no solid sample) showed the presence of MTBSTFA in the system. MTBSTFA was first detected in the EGA-QMS analysis blank then by GC-TCD-QMS analysis. This means that MTBSTFA is part of the background signal under its gaseous phase and is derived from at least one of the seven MTBSTFA/DMF derivatization cups in SAM. Since MTBSTFA is able to react in the gaseous phase, its detection implies the possibility to have some MTBSTFA reactions with all the labile compounds possibly present in the Martian soil, in the sampling system and/or inside the SAM instrument. In addition, we also have observed the presence of compounds resulting from the derivatization reaction between MTBSTFA and water. Indeed, water has been detected by two ways: the EGA experiment and the GC-TCD-MS run. Due to the presence of mono- and bi-silylated water derivatives, several characteristic ions can be detected in the EGA mode (e.g. m/z = 147, 73), and two characteristic peaks in the GC-TCD-MS analysis are also observed. In addition to water, a sylilated chloride compound has been detected after pyrolysis of the Rocknest soil. This compound is the simplest chloride derivative compound: chloro(1,1-dimethylethyl)dimethyl-silane, and it co-elutes with the mono-sylilated water derivative. [1] Buch, A. et al. (2009) J chrom. A, 43, 143-151. [2] Stalport, F. et al. (2012) Planet. Space Sci. 67: 1-13. [3] Geffroy-Rodier, C. et al. (2009) JAAP, 85, 454-459.

Buch, Arnaud; Freissinet, Caroline; Szopa, Cyril; Glavin, Danny; Coll, Patrice; Cabane, Michel; Eigenbrode, Jen; Navarro-Gonzalez, Rafael; Stern, Jen; Coscia, David; Teinturier, Samuel; Dworkin, Jason; Mahaffy, Paul; MSL Science Team

2013-04-01

328

Planetary and Space Science 55 (2007) 383400 The ORGANICS experiment on BIOPAN V: UV and space exposure  

E-print Network

) on the EXPOSE facility on the International Space Station (ISS). For the small fluence that was collected during; International Space Station; Photo-stability 1. Introduction Carbon chemistry in space occurs most efficientlyPlanetary and Space Science 55 (2007) 383­400 The ORGANICS experiment on BIOPAN V: UV and space

2007-01-01

329

Chemistry  

NSDL National Science Digital Library

These sites willhelp you gain greater understanding of Chemistry! Weather is also available Three areas to be on the test. STUDY HARD!!!! Equations Types of Equations Types of Equations text/htmlMichigan Teacher Network Matter Density of solids Density of solids text/htmlICSD ScienceZone Metals Kidneys and Metals Problem Set Kidneys and Metals Problem Set image/tiffCenter for Digital Curriculum Research POTENTIAL SURROGATE METALS FOR INCINERATOR TRIAL BURNS POTENTIAL SURROGATE METALS FOR INCINERATOR TRIAL BURNS text/html Let it snow Interactive Weather Maker Interactive Weather Maker urlexample ...

Riley

2006-04-22

330

An Advanced Undergraduate Chemistry Laboratory Experiment Exploring NIR Spectroscopy and Chemometrics  

ERIC Educational Resources Information Center

An advanced undergraduate chemistry laboratory experiment to study the advantages and hazards of the coupling of NIR spectroscopy and chemometrics is described. The combination is commonly used for analysis and process control of various ingredients used in agriculture, petroleum and food products.

Wanke, Randall; Stauffer, Jennifer

2007-01-01

331

Application of Calibrated Peer Review (CPR) Writing Assignments to Enhance Experiments with an Environmental Chemistry Focus  

ERIC Educational Resources Information Center

The browser-based software program, Calibrated Peer Review (CPR) developed by the Molecular Science Project enables instructors to create structured writing assignments in which students learn by writing and reading for content. Though the CPR project covers only one experiment in general chemistry, it might provide lab instructors with a method…

Margerum, Lawrence D.; Gulsrud, Maren; Manlapez, Ronald; Rebong, Rachelle; Love, Austin

2007-01-01

332

A Multi-Technique Forensic Experiment for a Nonscience-Major Chemistry Course  

ERIC Educational Resources Information Center

This multi-technique experiment with a forensic theme was developed for a nonscience-major chemistry course. The students are provided with solid samples and informed that the samples are either cocaine or a combination of drugs designed to mimic the stimulant and anesthetic qualities of cocaine such as caffeine and lidocaine. The students carry…

Szalay, Paul S.; Zook-Gerdau, Lois Anne; Schurter, Eric J.

2011-01-01

333

Absorption and Scattering Coefficients: A Biophysical-Chemistry Experiment Using Reflectance Spectroscopy  

ERIC Educational Resources Information Center

A biophysical-chemistry experiment, based on the reflectance spectroscopy for calculating the absorption and scattering coefficients of leaves is described. The results show that different plants species exhibit different values for both the coefficients because of their different pigment composition.

Cordon, Gabriela B.; Lagorio, M. Gabriela

2007-01-01

334

Review of intermediate-scale experiments for subsurface microbiology and chemistry  

Microsoft Academic Search

A workshop sponsored by the US Department of Energy (DOE) and Pacific Northwest Laboratory (PNL) was held at the University of Delaware's Virden Center in Lewes, Delaware, on April 12--14, 1987. The objectives of the workshop were to determine whether intermediate-scale experiments on subsurface microbiology and chemistry could advance scientific understanding of contaminant transport processes in groundwater, and the types

G. P. Streile; J. M. Zachara; J. K. Fredrickson

1987-01-01

335

Liquid-Liquid Extraction of Insecticides from Juice: An Analytical Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

A laboratory experiment was developed to target analytical chemistry students and to teach them about insecticides in food, sample extraction, and cleanup. Micro concentrations (sub-microgram/mL levels) of 12 insecticides spiked into apple juice samples are extracted using liquid-liquid extraction and cleaned up using either a primary-secondary…

Radford, Samantha A.; Hunter, Ronald E., Jr.; Barr, Dana Boyd; Ryan, P. Barry

2013-01-01

336

Molecular Orbitals of NO, NO[superscript+], and NO[superscript-]: A Computational Quantum Chemistry Experiment  

ERIC Educational Resources Information Center

This computational experiment presents qualitative molecular orbital (QMO) and computational quantum chemistry exercises of NO, NO[superscript+], and NO[superscript-]. Initially students explore several properties of the target molecules by Lewis diagrams and the QMO theory. Then, they compare qualitative conclusions with EHT and DFT calculations…

Orenha, Renato P.; Galembeck, Sérgio E.

2014-01-01

337

Nitration of Phenols Using Cu(NO[subscript 3])[subscript 2]: Green Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

An easy-to-complete, microwave-assisted, green chemistry, electrophilic nitration method for phenol using Cu(NO[subscript 3])[subscript 2] in acetic acid is discussed. With this experiment, students clearly understand the mechanism underlying the nitration reaction in one laboratory session. (Contains 4 schemes.)

Yadav, Urvashi; Mande, Hemant; Ghalsasi, Prasanna

2012-01-01

338

Computational Modeling of the Optical Rotation of Amino Acids: An "in Silico" Experiment for Physical Chemistry  

ERIC Educational Resources Information Center

A computational experiment that investigates the optical activity of the amino acid valine has been developed for an upper-level undergraduate physical chemistry laboratory course. Hybrid density functional theory calculations were carried out for valine to confirm the rule that adding a strong acid to a solution of an amino acid in the l…

Simpson, Scott; Autschbach, Jochen; Zurek, Eva

2013-01-01

339

Assessment of Antioxidant Capacities in Foods: A Research Experience for General Chemistry Students  

ERIC Educational Resources Information Center

With the booming interest in health food and nutrition, investigations of the antioxidant capacities of various foods have come to the forefront of food science. This general chemistry laboratory curriculum provides students with an opportunity to design and implement their own experiments relating to antioxidants in food. The curriculum is six…

Hoch, Matthew A.; Russell, Cianan B.; Steffen, Debora M.; Weaver, Gabriela C.; Burgess, John R.

2009-01-01

340

Determination of Mercury in Milk by Cold Vapor Atomic Fluorescence: A Green Analytical Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

Green analytical chemistry principles were introduced to undergraduate students in a laboratory experiment focused on determining the mercury concentration in cow and goat milk. In addition to traditional goals, such as accuracy, precision, sensitivity, and limits of detection in method selection and development, attention was paid to the…

Armenta, Sergio; de la Guardia, Miguel

2011-01-01

341

A Stopped-Flow Kinetics Experiment for the Physical Chemistry Laboratory Using Noncorrosive Reagents  

ERIC Educational Resources Information Center

Stopped-flow kinetics techniques are important to the study of rapid chemical and biochemical reactions. Incorporation of a stopped-flow kinetics experiment into the physical chemistry laboratory curriculum would therefore be an instructive addition. However, the usual reactions studied in such exercises employ a corrosive reagent that can over…

Prigodich, Richard V.

2014-01-01

342

Surface Enhanced Raman Spectroscopy: A Novel Physical Chemistry Experiment for the Undergraduate Laboratory  

Microsoft Academic Search

Raman spectra of molecules adsorbed on metal colloids exhibit large signal enhancements over those of the pure or solution phase samples. This paper presents background information on surface-enhanced Raman spectroscopy (SERS) and provides details for carrying out an SERS experiment in the undergraduate physical chemistry laboratory. A single system, pyridine on silver, has been adapted from the research literature for

Gabriela C. Weaver; Karen Norrod

1998-01-01

343

A global inventory of stratospheric fluorine in 2004 based on Atmospheric Chemistry Experiment Fourier transform spectrometer  

E-print Network

A global inventory of stratospheric fluorine in 2004 based on Atmospheric Chemistry Experiment 29 June 2006; accepted 7 August 2006; published 30 November 2006. [1] Total fluorine (FTOT by estimates of 15 minor fluorine species. Using these data, separate fluorine budgets were determined in five

Nassar, Ray

344

Coloring a Superabsorbent Polymer with Metal Ions: An Undergraduate Chemistry Experiment  

ERIC Educational Resources Information Center

A novel undergraduate chemistry experiment involving superabsorbent polymers commonly used in diapers and other personal care products is described. Students observe the removal of divalent transition-metal ions from aqueous solutions by the polymers. With the procedures provided, students are able to color the superabsorbent polymers with metal…

Yaung, Jing-Fun; Chen, Yueh-Huey

2009-01-01

345

Measurement of the Compressibility Factor of Gases: A Physical Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

In this article, we describe an experiment for the undergraduate physical chemistry laboratory in which students measure the compressibility factor of two gases, helium and carbon dioxide, as a function of pressure at constant temperature. The experimental apparatus is relatively inexpensive to construct and is described and diagrammed in detail.…

Varberg, Thomas D.; Bendelsmith, Andrew J.; Kuwata, Keith T.

2011-01-01

346

EPR Studies of Spin-Spin Exchange Processes: A Physical Chemistry Experiment.  

ERIC Educational Resources Information Center

Theoretical background, experimental procedures, and analysis of experimental results are provided for an undergraduate physical chemistry experiment on electron paramagnetic resonance (EPR) linewidths. Source of line broadening observed in a spin-spin exchange process between radicals formed in aqueous solutions of potassium peroxylamine…

Eastman, Michael P.

1982-01-01

347

A Practical and Convenient Diffusion Apparatus: An Undergraduate Physical Chemistry Experiment.  

ERIC Educational Resources Information Center

Described is a diffusion apparatus to be used in an undergraduate physical chemistry laboratory experiment to determine the diffusion coefficients of aqueous solutions of sucrose and potassium dichromate. Included is the principle of the method, apparatus design and description, and experimental procedure. (Author/DS)

Clifford, Ben; Ochiai, E. I.

1980-01-01

348

Suitable Class Experiments in Biochemistry for High-school Chemistry and Biology Courses.  

ERIC Educational Resources Information Center

Illustrates the scope of experimental investigations for biochemistry education in high school biology and chemistry courses. Gives a brief overview of biochemistry experiments with proteins, enzymes, carbohydrates, lipids, nucleic acids, vitamins, metabolism, electron transport, and photosynthesis including materials, procedures, and outcomes.…

Myers, A.

1987-01-01

349

An Attenuated Total Reflectance Sensor for Copper: An Experiment for Analytical or Physical Chemistry  

ERIC Educational Resources Information Center

A sensor experiment which can be applied to advanced undergraduate laboratory course in physical or analytical chemistry is described along with certain concepts like the demonstration of chemical sensing, preparation of thin films on a substrate, microtitration, optical determination of complex ion stoichiometry and isosbestic point. It is seen…

Shtoyko, Tanya; Zudans, Imants; Seliskar, Carl J.; Heineman, William R.; Richardson, John N.

2004-01-01

350

An Environmental Chemistry Experiment: The Determination of Radon Levels in Water.  

ERIC Educational Resources Information Center

Describes a radiation experiment developed to complement a new environmental chemistry laboratory curriculum. A scintillation counter is used to measure radon in water. The procedure relies on the fact that toluene will preferentially extract radon from water. Sample preparation is complete in less than 90 minutes. Because the level of…

Welch, Lawrence E.; Mossman, Daniel M.

1994-01-01

351

Varying responses of insect herbivores to altered plant chemistry under organic and conventional treatments.  

PubMed

The hypothesis that plants supplied with organic fertilizers are better defended against insect herbivores than those supplied with synthetic fertilizers was tested over two field seasons. Organic and synthetic fertilizer treatments at two nitrogen concentrations were supplied to Brassica plants, and their effects on the abundance of herbivore species and plant chemistry were assessed. The organic treatments also differed in fertilizer type: a green manure was used for the low-nitrogen treatment, while the high-nitrogen treatment contained green and animal manures. Two aphid species showed different responses to fertilizers: the Brassica specialist Brevicoryne brassicae was more abundant on organically fertilized plants, while the generalist Myzus persicae had higher populations on synthetically fertilized plants. The diamondback moth Plutella xylostella (a crucifer specialist) was more abundant on synthetically fertilized plants and preferred to oviposit on these plants. Glucosinolate concentrations were up to three times greater on plants grown in the organic treatments, while foliar nitrogen was maximized on plants under the higher of the synthetic fertilizer treatments. The varying response of herbivore species to these strong differences in plant chemistry demonstrates that hypotheses on defence in organically grown crops have over-simplified the response of phytophagous insects. PMID:19906673

Staley, Joanna T; Stewart-Jones, Alex; Pope, Tom W; Wright, Denis J; Leather, Simon R; Hadley, Paul; Rossiter, John T; van Emden, Helmut F; Poppy, Guy M

2010-03-01

352

The Titan Haze Simulation experiment on COSmIC: Probing Titan's atmospheric chemistry at low temperature  

NASA Astrophysics Data System (ADS)

The aim of the Titan Haze Simulation (THS) experiment is to contribute to a better understanding of aerosol formation in Titan's atmosphere through the study of the chemical formation pathways that link the simpler gas phase molecules resulting from the first steps of the N2-CH4 chemistry, to the more complex gas phase precursors of aerosols; and more specifically, to investigate the role of polycyclic aromatic hydrocarbons (PAHs) and nitrogenated polycyclic aromatic hydrocarbons (PANHs), among other hydrocarbons, in this process. In the THS experiment developed at the NASA Ames Cosmic simulation facility (COSmIC), Titan's atmospheric chemistry is simulated by a pulsed plasma jet expansion at temperature conditions (?150 K) close to those found in Titan's atmosphere in regions where aerosols are formed. In addition, because of the very short residence time of the gas in the plasma discharge, only the initial steps of the chemistry occur, making the COSmIC/THS a unique tool to study the first and intermediate (when adding heavier precursors to the initial N2-CH4 mixture) steps of Titan's atmospheric chemistry at low temperature as shown in the study presented here. We further illustrate the potential of COSmIC/THS for the simulation of Titan's atmospheric chemistry by presenting very promising results from a preliminary comparison of the laboratory data to data from the Cassini Plasma Spectrometer-Ion Beam Spectrometer (CAPS-IBS) instrument.

Sciamma-O'Brien, Ella; Ricketts, Claire L.; Salama, Farid

2014-11-01

353

Catalysis and Organometallic Chemistry of Rhodium and Iridium in the Oxidation of Organic Substrates  

Microsoft Academic Search

The purpose of this chapter is to present a survey of the organometallic chemistry and catalysis\\u000a of rhodium and iridium related to the oxidation of organic substrates that has been developed over the last\\u000a 5 years, placing special emphasis on reactions or processes involving environmentally friendly oxidants.\\u000a Iridium-based catalysts appear to be promising candidates for the oxidation of alcohols to aldehydes\\/ketones\\u000a as

Cristina Tejel; Miguel Ciriano

354

PREREQUIREMENTS: Chemical bond and Matter structure, Linear Algebra, Mathematics, Digital Calculus, Data processing fundamentals, Differential Calculus, Chemiometry, Physical Chemistry (Advanced), inorganic Chemistry, Biochemistry, Organic Chemistry (Advanced) PREVIOUS KNOWLEDGES: The corresponding to prerequirement courses, in particular the acquired as mathematics, statistics, optimisation, quantum mechanics and spectroscopy  

Microsoft Academic Search

milestone of scientific knowledge. From nineties, the evolution of computers has allowed the useful and effective incorporation of modelization in the chemical environment. Computational Chemistry. Computational Chemistry is an area of multidisciplinary knowledge. Different areas like Data Processing and Documentation, Mathematics (optimisation, operator algebra, calculus, differential equations, etc.), Physics and Physical Chemistry, Quantum chemistry, biochemistry, organic, inorganic and analytical chemistry

Jordi Teixidó Closa

355

Grade/Performance Contracts, Enhanced Communication, Cooperative Learning and Student Performance in Undergraduate Organic Chemistry  

NASA Astrophysics Data System (ADS)

This paper describes a grade/study-performance contract that was designed to increase student retention while maintaining academic performance levels in undergraduate organic chemistry. The experimental course included enhanced communication using electronic mail, and cooperative learning in addition to grade/study-performance contracts. The objective of the grade/study-performance contract was the development of learning skills with creation of a basis for unobtrusive auditing of performance. The retention rate in the experimental course was 0.82 for the first term and 0.93 for the second term. The overall retention was 0.76. This value was 3.8 times the average retention for the same sequence in the previous five years at the same institution. It was seven standard deviations away from the previous mean. The ACS Organic Chemistry Examination percentile score for the control section was 46+25 (n=117). The corresponding data for the experimental section was 53+23 (n=143). When the course was offered with the same instructor, cooperative learning, e-mail, but no grade/study-performance contract the ACS Exam percentile average 37+29. This represents a drop of 9.9 standard deviations for comparison of the means. We conclude that grade/study-performance contracts can be effective in increasing both student performance and retention in undergraduate organic chemistry.

Dougherty, Ralph C.

1997-06-01

356

Laboratory Studies of the Reactive Chemistry and Changing CCN Properties of Secondary Organic Aerosol, Including Model Development  

SciTech Connect

The chemical evolution of secondary-organic-aerosol (SOA) particles and how this evolution alters their cloud-nucleating properties were studied. Simplified forms of full Koehler theory were targeted, specifically forms that contain only those aspects essential to describing the laboratory observations, because of the requirement to minimize computational burden for use in integrated climate and chemistry models. The associated data analysis and interpretation have therefore focused on model development in the framework of modified kappa-Koehler theory. Kappa is a single parameter describing effective hygroscopicity, grouping together several separate physicochemical parameters (e.g., molar volume, surface tension, and van't Hoff factor) that otherwise must be tracked and evaluated in an iterative full-Koehler equation in a large-scale model. A major finding of the project was that secondary organic materials produced by the oxidation of a range of biogenic volatile organic compounds for diverse conditions have kappa values bracketed in the range of 0.10 +/- 0.05. In these same experiments, somewhat incongruently there was significant chemical variation in the secondary organic material, especially oxidation state, as was indicated by changes in the particle mass spectra. Taken together, these findings then support the use of kappa as a simplified yet accurate general parameter to represent the CCN activation of secondary organic material in large-scale atmospheric and climate models, thereby greatly reducing the computational burden while simultaneously including the most recent mechanistic findings of laboratory studies.

Scot Martin

2013-01-31

357

3D-printed devices for continuous-flow organic chemistry  

PubMed Central

Summary We present a study in which the versatility of 3D-printing is combined with the processing advantages of flow chemistry for the synthesis of organic compounds. Robust and inexpensive 3D-printed reactionware devices are easily connected using standard fittings resulting in complex, custom-made flow systems, including multiple reactors in a series with in-line, real-time analysis using an ATR-IR flow cell. As a proof of concept, we utilized two types of organic reactions, imine syntheses and imine reductions, to show how different reactor configurations and substrates give different products. PMID:23766811

Dragone, Vincenza; Sans, Victor; Rosnes, Mali H; Kitson, Philip J

2013-01-01

358

3D-printed devices for continuous-flow organic chemistry.  

PubMed

We present a study in which the versatility of 3D-printing is combined with the processing advantages of flow chemistry for the synthesis of organic compounds. Robust and inexpensive 3D-printed reactionware devices are easily connected using standard fittings resulting in complex, custom-made flow systems, including multiple reactors in a series with in-line, real-time analysis using an ATR-IR flow cell. As a proof of concept, we utilized two types of organic reactions, imine syntheses and imine reductions, to show how different reactor configurations and substrates give different products. PMID:23766811

Dragone, Vincenza; Sans, Victor; Rosnes, Mali H; Kitson, Philip J; Cronin, Leroy

2013-01-01

359

The impact of recirculation, ventilation and filters on secondary organic aerosols generated by indoor chemistry  

NASA Astrophysics Data System (ADS)

This study examined the impact of recirculation rates (7 and 14 h -1), ventilation rates (1 and 2 h -1), and filtration on secondary organic aerosols (SOAs) generated by ozone of outdoor origin reacting with limonene of indoor origin. Experiments were conducted within a recirculating air handling system that serviced an unoccupied, 236 m 3 environmental chamber configured to simulate an office; either no filter, a new filter or a used filter was located downstream of where outdoor air mixed with return air. For otherwise comparable conditions, the SOA number and mass concentrations at a recirculation rate of 14 h -1 were significantly smaller than at a recirculation rate of 7 h -1. This was due primarily to lower ozone concentrations, resulting from increased surface removal, at the higher recirculation rate. Increased ventilation increased outdoor-to-indoor transport of ozone, but this was more than offset by the increased dilution of SOA derived from ozone-initiated chemistry. The presence of a particle filter (new or used) strikingly lowered SOA number and mass concentrations compared with conditions when no filter was present. Even though the particle filter in this study had only 35% single-pass removal efficiency for 100 nm particles, filtration efficiency was greatly amplified by recirculation. SOA particle levels were reduced to an even greater extent when an activated carbon filter was in the system, due to ozone removal by the carbon filter. These findings improve our understanding of the influence of commonly employed energy saving procedures on occupant exposures to ozone and ozone-derived SOA.

Fadeyi, M. O.; Weschler, C. J.; Tham, K. W.

360

Research and Teaching: A Performance Enhanced Interactive Learning Workshop Model as a Supplement for Organic Chemistry Instruction  

NSDL National Science Digital Library

In this study, the authors describe a Performance Enhanced Interactive Learning (PEIL) workshop model as a supplement for organic chemistry instruction. This workshop model differs from many others in that it includes public presentations by students and

Jilliam Grose-Fifer

2011-01-01

361

Organic Aerosol Formation in the Humid, Photochemically-Active Southeastern US: SOAS Experiments and Simulations  

NASA Astrophysics Data System (ADS)

Aqueous multiphase chemistry in the atmosphere can lead to rapid transformation of organic compounds, forming highly oxidized low volatility organic aerosol and, in some cases, light absorbing (brown) carbon. Because liquid water is globally abundant, this chemistry could substantially impact climate, air quality, health, and the environment. Gas-phase precursors released from biogenic and anthropogenic sources are oxidized and fragmented forming water-soluble gases that can undergo reactions in the aqueous phase (in clouds, fogs, and wet aerosols) leading to the formation of secondary organic aerosol (SOAAQ). Recent studies have highlighted the role of certain precursors like glyoxal, methylglyoxal, glycolaldehyde, acetic acid, acetone, and epoxides in the formation of SOAAQ. The goal of this work is to identify other precursors that are atmospherically important. In this study, ambient mixtures of water-soluble gases were scrubbed from the atmosphere at Brent, Alabama during the Southern Oxidant and Aerosol Study (SOAS). Four mist chambers in parallel collected ambient gases in a DI water medium at 20-25 LPM with a 4 hr collection time. Total organic carbon (TOC) values in daily composited samples were 64-180 ?M. Aqueous OH radical oxidation experiments were conducted with these mixtures in a newly designed cuvette chamber to understand the formation of SOA through gas followed by aqueous chemistry. OH radicals (3.5E-2 ?M [OH] s-1) were formed in-situ in the chamber, continuously by H2O2 photolysis. Precursors and products of these aqueous OH experiments were characterized using ion chromatography (IC), electrospray ionization mass spectrometry (ESI-MS), and IC-ESI-MS. ESI-MS results from a June 12th, 2013 sample showed precursors to be primarily odd, positive mode ions, indicative of the presence of non-nitrogen containing alcohols, aldehydes, organic peroxides, or epoxides. Products were seen in the negative mode and included organic acid ions like pyruvate and oxalate. The results from this study will be used to better understand aqueous chemistry in clouds/fogs and to identify precursors for laboratory study of wet aerosol, fog, and cloud chemistry.

Sareen, N.; Lim, Y. B.; Carlton, A. G.; Turpin, B. J.

2013-12-01

362

Seasonal Carbonate Chemistry Covariation with Temperature, Oxygen, and Salinity in a Fjord Estuary: Implications for the Design of Ocean Acidification Experiments  

PubMed Central

Carbonate chemistry variability is often poorly characterized in coastal regions and patterns of covariation with other biologically important variables such as temperature, oxygen concentration, and salinity are rarely evaluated. This absence of information hampers the design and interpretation of ocean acidification experiments that aim to characterize biological responses to future pCO2 levels relative to contemporary conditions. Here, we analyzed a large carbonate chemistry data set from Puget Sound, a fjord estuary on the U.S. west coast, and included measurements from three seasons (winter, summer, and fall). pCO2 exceeded the 2008–2011 mean atmospheric level (392 µatm) at all depths and seasons sampled except for the near-surface waters (< 10 m) in the summer. Further, undersaturated conditions with respect to the biogenic carbonate mineral aragonite were widespread (?ar<1). We show that pCO2 values were relatively uniform throughout the water column and across regions in winter, enriched in subsurface waters in summer, and in the fall some values exceeded 2500 µatm in near-surface waters. Carbonate chemistry covaried to differing levels with temperature and oxygen depending primarily on season and secondarily on region. Salinity, which varied little (27 to 31), was weakly correlated with carbonate chemistry. We illustrate potential high-frequency changes in carbonate chemistry, temperature, and oxygen conditions experienced simultaneously by organisms in Puget Sound that undergo diel vertical migrations under present-day conditions. We used simple calculations to estimate future pCO2 and ?ar values experienced by diel vertical migrators based on an increase in atmospheric CO2. Given the potential for non-linear interactions between pCO2 and other abiotic variables on physiological and ecological processes, our results provide a basis for identifying control conditions in ocean acidification experiments for this region, but also highlight the wide range of carbonate chemistry conditions organisms may currently experience in this and similar coastal ecosystems. PMID:24586915

Reum, Jonathan C. P.; Alin, Simone R.; Feely, Richard A.; Newton, Jan; Warner, Mark; McElhany, Paul

2014-01-01

363

Teaching innovation in organic chemistry: An inquiry into what happens when the lecturer stops lecturing  

NASA Astrophysics Data System (ADS)

In this dissertation the author presents findings from a study of an organic chemistry class in which the instructor changed his mode of content delivery. Instead of using a traditional lecture, the professor engaged students in discussions about chemical behavior, required students to complete cooperative learning activities in and out of class, and altered his examination format. The purpose of the research was to investigate the implementation of the changes made in content delivery, describe subsequent classroom interactions, and discuss participant responses to the innovations. Because of the research focus the author used a qualitative methodology to investigate this unique organic chemistry course. The study showed that the instructor's belief system and skills played an important role in overcoming barriers to implementation. Analysis of class transcripts revealed that the class was highly interactive with students freely offering responses to the instructor's questions and sometimes submitting insightful comments. The discussion format of the class also revealed some student misunderstanding that other teaching structures may not have identified. In general the instructor was able to pursue some concepts in more depth than allowed by a typical lecture mode of content delivery. Analysis of class transcripts also showed characteristics of organic chemistry teaching by Prof. Loudon that might be described as exemplary. He focused student attention on molecular structure and the chemical behavioral patterns that emerge from organic compounds that are structurally similar. Student response to Prof. Loudon's teaching style was quite favorable. A common remark from students was that his personal knowledge of them contributed to their class preparation and desire to learn. In general, students appreciated the opportunity to discuss exam questions in their groups before individual exam administration. On the final course evaluation, however, a couple students expressed disdain towards the exam format stating that sometimes fellow group members led them astray. Several also said that the discussion contributed to anxiety instead of making the examination period more relaxed as Prof. Loudon had hoped.

Bauer, Richard Charles

1998-12-01

364

Atmospheric chemistry of oxygenated organic compounds. Final report, October 1995--September 1998  

SciTech Connect

The newly revised ozone and particulate matter regulations will impact decisions on chemical substitution and formulation selection for the Air Force and DoD. Removal of toxic organics and halogenated organics from formulations has been the primary method to meet these new regulatory burdens. However, the substitutes which consist mainly of oxygenated organic compounds (alcohol, aldehydes, ketones and acetates) have poorly understood environmental impacts. To bridge this knowledge gap, investigations into the atmospheric chemistry of this useful class of compounds has begun. New information presented in this report demonstrates the wide variety of rate constants and transformation mechanisms observed. It was also observed that certain molecular structures enhance hydroxyl radical reactions. These data are important for improving the air quality assessments of new substitutes and formulations and minimizing regulatory constraints.

Wells, J.R.; Baxley, J.S.; Wyatt, S.E.; Markgraf, S.J.

1998-10-01

365

Fostering Pre-service Teachers' Self-Determined Environmental Motivation Through Green Chemistry Experiments  

NASA Astrophysics Data System (ADS)

The global environmental crisis intensifies particularly in developing nations. Environmental educators have begun to understand that changing the environmental impact requires not only changes in pro-environmental knowledge and attitudes but also in associated, self-determined motivation. This study was designed to test the hypothesis that a green chemistry curriculum changes Malaysian pre-service teachers' environmental motivation. Two comparable groups of pre-service teachers participated in this study. The students in the experimental group ( N = 140) did green chemistry experiments whereas the control group ( N = 123) did equivalent experiments in a traditional manner. Posttest results indicate that there is significant difference between both the groups for intrinsic motivation, integration, identification, and introjections scales and no differences for external regulation and amotivation scales. The qualitative analysis of interview data suggests that the changes are predominantly due to the personal satisfaction that participants derived from engaging in pro-environmental behavior.

Karpudewan, Mageswary; Ismail, Zurida; Roth, Wolff-Michael

2012-10-01

366

"Crown Ether" Synthesis: An Organic Laboratory Experiment.  

ERIC Educational Resources Information Center

This experiment is designed to acquaint the student with a macromolecular synthesis of a crown ether type compound. The starting materials are readily available and the product, a cyclic polyether, belongs to a class of compounds that has aroused the interest of chemist and biologist alike. (Author/BB)

Field, Kurt W.; And Others

1979-01-01

367

State-of-the-Art-Symposium: Self-Organization in Chemistry.  

ERIC Educational Resources Information Center

Presents four articles dealing with chaotic systems. Lists sources for nine demonstrations or experiments dealing with self-organization. Provides a vocabulary review of self-organization. Describes three chemical oscillator models. Discusses the role of chaos in flow systems. (MVL)

Soltzberg, Leonard J.; And Others

1989-01-01

368

Identification of Primary, Secondary, and Tertiary Alcohols: An Experiment in Spectrophotometry, Organic Chemistry, and Analytical Chemistry  

Microsoft Academic Search

A simple method is presented that enables students to distinguish in a few minutes between primary, secondary and tertiary alkyl alcohols. This method is based on peculiarities of absorption spectra in the near-UV region of alkyl nitrites, the products of alcohol nitrosation. This procedure consists of adding 1-2 drops of alcohol to the acidified solution of NaNO2, extracting the nitrate

I. A. Leenson

1997-01-01

369

Identification of Primary, Secondary, and Tertiary Alcohols: An Experiment in Spectrophotometry, Organic Chemistry, and Analytical Chemistry  

NASA Astrophysics Data System (ADS)

A simple method is presented that enables students to distinguish in a few minutes between primary, secondary and tertiary alkyl alcohols. This method is based on peculiarities of absorption spectra in the near-UV region of alkyl nitrites, the products of alcohol nitrosation. This procedure consists of adding 1-2 drops of alcohol to the acidified solution of NaNO2, extracting the nitrate obtained with hydrocarbon solvent and taking the spectrum of a highly diluted nitrite solution in the same solvent. All tertiary nitrites have a maximum at ca. 400 nm whereas all primary and secondary nitrites do not have such a maximum. The discrimination between two latter nitrites is based on the ratio of the heights of two adjacent maxima at ca. 345 and 360 nm, this ratio being equal to 1.3-1.4 for 11 primary nitrites examined (with the exception of methylnitrite) and to 3.0-3.7 for 5 secondary nitrites. The semiquantitative method is also proposed for the analysis of primary and secondary alcohols in their mixture either with the calibration curve or with linear expression (the latter works well when the primary alcohol content in the mixture is more than 20%). The assignments are proposed for students, including nitrosation procedure, taking spectra, plotting graphs, deducing linear dependence and investigating of further possibilities of alcohol mixture analysis.

Leenson, I. A.

1997-04-01

370

The PROCESS experiment: an astrochemistry laboratory for solid and gaseous organic samples in low-earth orbit.  

PubMed

The PROCESS (PRebiotic Organic ChEmistry on the Space Station) experiment was part of the EXPOSE-E payload outside the European Columbus module of the International Space Station from February 2008 to August 2009. During this interval, organic samples were exposed to space conditions to simulate their evolution in various astrophysical environments. The samples used represent organic species related to the evolution of organic matter on the small bodies of the Solar System (carbonaceous asteroids and comets), the photolysis of methane in the atmosphere of Titan, and the search for organic matter at the surface of Mars. This paper describes the hardware developed for this experiment as well as the results for the glycine solid-phase samples and the gas-phase samples that were used with regard to the atmosphere of Titan. Lessons learned from this experiment are also presented for future low-Earth orbit astrochemistry investigations. PMID:22680688

Cottin, Hervé; Guan, Yuan Yong; Noblet, Audrey; Poch, Olivier; Saiagh, Kafila; Cloix, Mégane; Macari, Frédérique; Jérome, Murielle; Coll, Patrice; Raulin, François; Stalport, Fabien; Szopa, Cyril; Bertrand, Marylène; Chabin, Annie; Westall, Frances; Chaput, Didier; Demets, René; Brack, André

2012-05-01

371

VOC Source and Inflow Characterization during the Deep Convective Cloud and Chemistry (DC3) experiment  

NASA Astrophysics Data System (ADS)

More than 50 volatile organic compounds (VOCs) were measured during the Deep Convective Clouds and Chemistry Project (DC3) field campaign, which was based out of Salina, KS May 10 - June 30, 2012. DC3 investigated the impact of deep, mid-latitude continental convective clouds on upper tropospheric composition and chemistry. The UCI Whole Air Sampler (WAS) measured VOCs on board the NASA DC-8 aircraft and the NCAR Trace Organic Gas Analyzer (TOGA) measured VOCs on board the NSF GV. Coordinated flights between the two aircraft produced a rich dataset with which to characterize the inflow and outflow of convective events. While probing storm inflow, numerous natural and anthropogenic sources were encountered, including oil and gas wells in Colorado, Texas, and Oklahoma, biomass burning, biogenic VOC emissions, and other anthropogenic sources (urban, feedlots, etc). The significant and widespread influence of oil and gas activities dominated VOC alkane distributions during DC3, in both inflow and outflow, effectively illustrating the connection between emission and fast vertical transport of VOCs into the free troposphere. We present a mass balance analysis of a flight over TX and OK, which allowed us to estimate oil and gas emissions in that region. The results from this analysis will be compared to previous work in the same area, as well as to emissions from other oil and gas regions and to model simulations from the Community Atmosphere Model with Chemistry (CAM-chem).

Blake, N. J.; Hartt, G.; Barletta, B.; Simpson, I. J.; Schroeder, J.; Hung, Y.; Marrero, J.; Gartner, A.; Hirsch, C.; Meinardi, S.; Blake, D. R.; Zhang, Y.; Apel, E. C.; Hornbrook, R. S.; Campos, T. L.; Emmons, L. K.

2013-12-01

372

Review of intermediate-scale experiments for subsurface microbiology and chemistry  

SciTech Connect

A workshop sponsored by the US Department of Energy (DOE) and Pacific Northwest Laboratory (PNL) was held at the University of Delaware's Virden Center in Lewes, Delaware, on April 12--14, 1987. The objectives of the workshop were to determine whether intermediate-scale experiments on subsurface microbiology and chemistry could advance scientific understanding of contaminant transport processes in groundwater, and the types of experiments that are needed at the intermediate scale to advance the state of the art. The term ''intermediate-scale experiment'' refers to an experiment that would be conducted in a system that is intermediate to the field and a laboratory batch reactor or column. Intermediate-scale experiments were more rigorously defined at the workshop as those focusing on processes and phenomena operative at the mesoscopic scale. The concept of intermediate-scale research was discussed, but not critically reviewed, at a previous workshop. 4 refs.

Streile, G.P.; Zachara, J.M.; Fredrickson, J.K.

1987-01-01

373

Introduction to Homogenous Catalysis with Ruthenium-Catalyzed Oxidation of Alcohols: An Experiment for Undergraduate Advanced Inorganic Chemistry Students  

ERIC Educational Resources Information Center

A three-week laboratory experiment, which introduces students in an advanced inorganic chemistry course to air-sensitive chemistry and catalysis, is described. During the first week, the students synthesize RuCl[subscript 2](PPh[subscript 3])[subscript 3]. During the second and third weeks, the students characterize the formed coordination…

Miecznikowski, John R.; Caradonna, John P.; Foley, Kathleen M.; Kwiecien, Daniel J.; Lisi, George P.; Martinez, Anthony M.

2011-01-01

374

Meaningful Learning in a First-Year Chemistry Laboratory Course: Differences across Classical, Discovery, and Instrumental Experiments  

ERIC Educational Resources Information Center

At Miami University in Oxford, Ohio, the second-semester general chemistry course for chemistry majors is the equivalent of an analytical laboratory course. The experiments in the course are classified as classical, discovery, or instrumental on the basis of their structure and purpose. To investigate students' perceptions of learning through…

Emenike, Mary Elizabeth; Danielson, Neil D.; Bretz, Stacey Lowery

2011-01-01

375

A Fifty-Year Love Affair with Organic Chemistry (by William S. Johnson)  

NASA Astrophysics Data System (ADS)

This latest volume is the 20th in Jeff Seeman's projected 22-volume series of autobiographies of 20th-century organic chemists that began publication in 1990 (Kauffman, G. B. J. Chem. Educ. 1991, 68, A21). Unfortunately, Johnson did not live to see this volume in print. Ted Bartlett and Ray Conrow reviewed the final manuscript, galleys, and page proofs; and Ted Bartlett, Paul Bartlett, John D. Roberts, and Gilbert Stork contributed an epilogue that complements Johnson's own words, adds a warm, personal final touch that he was unable to provide, and incorporates his final research into the volume. Born in New Rochelle, New York, on February 24, 1913, William Summer Johnson attended Amherst College with the aid of a scholarship and various odd jobs such as tending furnace, washing dishes, and playing saxophone in dance bands (he seriously considered becoming a professional musician). Here he became enamored with organic chemistry, which he taught as an instructor for a year after his graduation magna cum laude in 1936. He then worked with a fellowship under Louis Fieser, who sparked his interest in steroids, at Harvard University, from which he received his M.A. (1938) and Ph.D. (1940) degrees. In 1940 Johnson joined the faculty at the University of Wisconsin, where he rose through the ranks, eventually becoming Homer Adkins Professor of Chemistry (1954-60). He began the total synthesis of steroids, the main subject of his life's work, "which soon proved to be the hottest synthetic target of the time". In 1960 he accepted an invitation to become head of and to upgrade the Stanford University Chemistry Department. With faculty recruiting as his primary concern, he was able to add Carl Djerassi, Paul J. Flory, Harden M. McConnell, Henry Taube, and Eugene E. van Tamelen to the department, resulting in its spectacular rise from 15th to 5th place in the nation. He remained at Stanford for the rest of his career, serving as department head for nine years. He died at the age of 82 on August 19, 1995. Johnson's book reads like a Who's Who of Organic Chemistry, with descriptions, impressions, and thumbnail sketches of such luminaries as Sir Robert Robinson, Robert B. Woodward, Gilbert Stork, Carl Djerassi, Derek Barton, John D. ("Jack") Roberts, and authors of other Profiles volumes. During his long and productive career, Johnson made many contributions to contemporary organic chemistry, the genesis and course of which he describes lucidly with extensive use of 110 structural formulas, 75 reaction schemes, and occasional laboratory notebook pages. Three hundred fifty-six graduate and undergraduate students, postdocs, and visiting professors (many of whom are shown in the 63 formal and informal photographs in the book) have worked with him through five and a half decades. In "Some Concluding Remarks about Our Research", Johnson states, "The reviewed research did not evolve from a master plan; indeed it was largely a matter of following one's nose and trying to look at things that related to areas that were regarded as important issues of the time." Johnson's intimate and revealing autobiography will not only appeal to synthetic organic chemists but will be of interest to both present and future generations of students and instructors of chemistry courses and the history of science as well as to all persons concerned with the human aspects of science.

Kauffman, Reviewed By George B.; Kauffman, Laurie M.

1999-12-01

376

Ozone and organic nitrates over the eastern United States: Sensitivity to isoprene chemistry  

NASA Astrophysics Data System (ADS)

implement a new isoprene oxidation mechanism in a global 3-D chemical transport model (GEOS-Chem). Model results are evaluated with observations for ozone, isoprene oxidation products, and related species from the International Consortium for Atmospheric Research on Transport and Transformation aircraft campaign over the eastern United States in summer 2004. The model achieves an unbiased simulation of ozone in the boundary layer and the free troposphere, reflecting canceling effects from recent model updates for isoprene chemistry, bromine chemistry, and HO2 loss to aerosols. Simulation of the ozone-CO correlation is improved relative to previous versions of the model, and this is attributed to a lower and reversible yield of isoprene nitrates, increasing the ozone production efficiency per unit of nitrogen oxides (NOx ? NO + NO2). The model successfully reproduces the observed concentrations of organic nitrates (?ANs) and their correlations with HCHO and ozone. ?ANs in the model is principally composed of secondary isoprene nitrates, including a major contribution from nighttime isoprene oxidation. The correlations of ?ANs with HCHO and ozone then provide sensitive tests of isoprene chemistry and argue in particular against a fast isomerization channel for isoprene peroxy radicals. ?ANs can provide an important reservoir for exporting NOx from the U.S. boundary layer. We find that the dependence of surface ozone on isoprene emission is positive throughout the U.S., even if NOx emissions are reduced by a factor of 4. Previous models showed negative dependences that we attribute to erroneous titration of OH by isoprene.

Mao, Jingqiu; Paulot, Fabien; Jacob, Daniel J.; Cohen, Ronald C.; Crounse, John D.; Wennberg, Paul O.; Keller, Christoph A.; Hudman, Rynda C.; Barkley, Michael P.; Horowitz, Larry W.

2013-10-01

377

Solvent Selection for Recrystallization: An Undergraduate Organic Experiment.  

ERIC Educational Resources Information Center

This experiment develops the students' ability to carry out a simple recrystallization effectively, and demonstrates how a solvent may be selected or rejected for the recrystallization of a specific organic compound. (Author/BB)

Baumann, Jacob B.

1979-01-01

378

Data Pooling in a Chemical Kinetics Experiment: The Aquation of a Series of Cobalt(III) Complexes--A Discovery Chemistry Experiment  

ERIC Educational Resources Information Center

An experiment in chemical kinetics as part of our Discovery Chemistry curriculum is described. Discovery Chemistry is a pedagogical philosophy that makes the laboratory the key center of learning for students in their first two years of undergraduate instruction. Questions are posed in the pre-laboratory discussion and assessed using pooled…

Herrick, Richard S.; Mills, Kenneth V.; Nestor, Lisa P.

2008-01-01

379

Preliminary findings of the Viking gas exchange experiment and a model for Martian surface chemistry  

NASA Technical Reports Server (NTRS)

Earlier results reported from the Viking Lander-1 experiment are reexamined and interpreted in terms of a model of the Martian soil surface morphology and chemistry. Major events in the gas exchange experiment (GEX) first cycle are tabulated and data are presented on the sample processing and transport environments experienced by the soil samples. Oxygen and CO2 evolved from humidified Martian soil in GEX and slight changes in N2 present are investigated. A soil model involving iron oxide coating on silicate material is entertained to yield a mechanistic explanation of the experimental findings, and invocation of biotic processes is eschewed.

Oyama, V. I.; Berdahl, B. J.; Carle, G. C.

1977-01-01

380

Detonation chemistry apparatus experiments with nonreactive liquids, reactive liquids, and a reactive solid  

SciTech Connect

The detonation chemistry apparatus was designed to analyze the results of detonating small quantities of explosives or the results of rapidly mixing reactants. The diagnostics are rapid Schlieren photography of the emitted plume (up to 10 photographs per microsecond) and rapid mass spectroscopy (12 {micro}s per scan). The authors report here the results of a series of experiments with two liquids that do not react exothermically and another series with liquids that do react exothermically. They also report some experiments with a solid reactant, Teflon.

Lyman, J.; Fry, H.; Breshears, D.; Romero, J.

1996-05-01

381

Experiment Results Microspectroscopy of Meteorites: Search for Organic Mineral Correlations  

E-print Network

Experiment Results Microspectroscopy of Meteorites: Search for Organic ­ Mineral Correlations M on the mineral species. Little is known about the spatial distribution and mineralogical relationships of organic molecules in meteorites. The amount and type of such molecules may depend on the mineral species

Peale, Robert E.

382

A new Geoengineering Model Intercomparison Project (GeoMIP) experiment designed for climate and chemistry models  

NASA Astrophysics Data System (ADS)

A new Geoengineering Model Intercomparison Project (GeoMIP) experiment "G4 specified stratospheric aerosols" (short name: G4SSA) is proposed to investigate the impact of stratospheric aerosol geoengineering on atmosphere, chemistry, dynamics, climate, and the environment. In contrast to the earlier G4 GeoMIP experiment, which requires an emission of sulfur dioxide (SO2) into the model, a prescribed aerosol forcing file is provided to the community, to be consistently applied to future model experiments between 2020 and 2100. This stratospheric aerosol distribution, with a total burden of about 2 Tg S has been derived using the ECHAM5-HAM microphysical model, based on a continuous annual tropical emission of 8 Tg SO2 yr-1. A ramp-up of geoengineering in 2020 and a ramp-down in 2070 over a period of 2 years are included in the distribution, while a background aerosol burden should be used for the last 3 decades of the experiment. The performance of this experiment using climate and chemistry models in a multi-model comparison framework will allow us to better understand the impact of geoengineering and its abrupt termination after 50 years in a changing environment. The zonal and monthly mean stratospheric aerosol input data set is available at https://www2.acd.ucar.edu/gcm/geomip-g4-specified-stratospheric-aerosol-data-set.

Tilmes, S.; Mills, M. J.; Niemeier, U.; Schmidt, H.; Robock, A.; Kravitz, B.; Lamarque, J.-F.; Pitari, G.; English, J. M.

2015-01-01

383

Stereochemical Control in Carbohydrate Chemistry  

ERIC Educational Resources Information Center

Carbohydrates, in the form of glycoconjugates, have recently been shown to control a wide range of cellular processes. Accordingly, students interested in the study of organic chemistry and biomedical sciences should be exposed to carbohydrate chemistry. To this end, we have developed a sequence of experiments that leads the student from the…

Batchelor, Rhys; Northcote, Peter T.; Harvey, Joanne E.; Dangerfield, Emma M.; Stocker, Bridget L.

2008-01-01

384

Pollution Prevention Plan for the Y-12 Analytical Chemistry Organization Off-Site Union Valley Facility  

SciTech Connect

The Y-12 Analytical Chemistry Organization (ACO) Off-Site Union Valley Facility (Union Valley Facility) is managed by Babcock and Wilcox Technical Services Y-12, L.L.C. (B and W Y-12) through the Y-12 National Security Complex organization. Accordingly, the Y-12 Pollution Prevention Program encompasses the operations conducted at the Union Valley Facility. The Y-12 Program is designed to fully comply with state, federal and U.S. Department of Energy (DOE) requirements concerning waste minimization/pollution prevention as documented in the Y-12 Pollution Prevention Program Plan. The Program is formulated to reduce the generation and toxicity of all Y-12 wastes in all media, including those wastes generated by the Union Valley Facility operations. All regulatory and DOE requirements are met by the Y-12 Program Plan.

Jackson, J. G.

2010-03-01

385

Ligand chemistry of titania precursor affects transient photovoltaic behavior in inverted organic solar cells  

NASA Astrophysics Data System (ADS)

The chemistry of the precursor from which charge transport layers are formed can significantly affect the device performance of organic solar cells. Here, we compare two common precursors that are used to generate titania electron transport layers and elucidate their effects on the transient characteristics of inverted bulk-heterojunction polymer solar cells comprising poly(3-hexyl hiophene) and [6,6]-phenyl-C61-butyric acid methyl ester. Substituting the isopropyl ligands of titanium isopropoxide with 2-methoxyethanol leads to electron transport layers that require a shorter illumination time to fill shallow electron traps. Furthermore, organic solar cells with titania electron transport layers prepared with such pre-modified titania precursor exhibit higher power-conversion efficiencies stemming from lower trap densities.

Bok Kim, Jong; Ahn, Seokhoon; Ju Kang, Seok; Nuckolls, Colin; Loo, Yueh-Lin

2013-03-01

386

The Role of Radiation in the Solar Nebula: Correlated Chemistry-Structure- Isotope Studies of Laboratory and Extraterrestrial Organics  

NASA Astrophysics Data System (ADS)

This proposal outlines an interdisciplinary effort aimed at quantitatively evaluating the roles that irradiation played in the evolution of ices and organics in the solar nebula and the potential trapping of noble gases in primitive solids. The collective effort outlined here and in two partnered proposals (PIs Scott Sandford and Fred Ciesla) involves individuals at five primary institutions. We define a series of coordinated experimental, theoretical, and observational projects that are necessary to begin to recognize and understand the complex effects of irradiation in the early Solar System. This coordinated effort is in line with the latest emphasis on interdisciplinary work by the Origins of Solar System program. The specific goal of the CIW-NRL component of the effort is to conduct comparative studies of the isotope composition, chemistry and structure of organic residues from ices subjected to controlled radiation exposures, with those of organic matter in primitive Solar System materials, primarily interplanetary dust particles (IDPs). Three broad tasks will be undertaken: 1) Evaluate the extent to which organic molecules were formed and restructured as they and their icy precursors were irradiated by UV, x-rays and cosmic-rays in the solar nebula. Specifically, we will revisit the model of Ciesla and Sandford (Science, 2012), and evaluate the irradiation doses seen by ices and organics in the disk, as well as the chemical evolution of these species as they move through more realistic disk structures. The detailed consequences of this irradiation, as well as the rates and fluences required to drive changes in chemistry and physical structure, will be determined by complementary experiments and analytic studies. 2) Quantitatively explore the history of noble gases in ices and organics in the outer solar nebula as water ice is desorbed (due to thermal or photo effects) and reformed in the solar nebula. We will also explore how such ices are irradiated and the structural changes that occur in these ices and resulting photo-products. We will determine the extent to which noble gases remain trapped in these ices after processing and in the residues that form from this irradiation, and the extent to which this residue replicates the properties of the enigmatic phase Q carrier of noble gases in meteorites. 3) Determine the isotopic effects of C, H, and N induced by irradiation of ices and organics. We will carry out experiments to determine how enrichments in heavy isotopes may be passed forward from target ices into organics and the extent to which irradiation itself results in isotopic differences between target materials and residues. These results will be combined with dynamical models to determine the range of isotopic ratios expected from irradiative processing in the solar nebula. Each of these experimental and theoretical tasks will be complemented by coordinated microanalytical (chemical-microstructural-isotopic) studies of relevant, naturally- occurring, organic matter in anhydrous chondritic porous IDPs and, if available, ultracarbonaceous micrometeorites. Both are among the most primitive planetary materials available for laboratory study. These observations will be used to better understand the range of properties of early Solar System organic matter and to directly search for evidence of the radiation processing signatures identified by the three major tasks above. Thus, the IDP and micrometeorite analyses are necessary to provide ground-truth for the extensive theoretical and experimental work.

Nittler, Larry

387

Distinct optical chemistry of dissolved organic matter in urban pond ecosystems.  

PubMed

Urbanization has the potential to dramatically alter the biogeochemistry of receiving freshwater ecosystems. We examined the optical chemistry of dissolved organic matter (DOM) in forty-five urban ponds across southern Ontario, Canada to examine whether optical characteristics in these relatively new ecosystems are distinct from other freshwater systems. Dissolved organic carbon (DOC) concentrations ranged from 2 to 16 mg C L(-1) across the ponds with an average value of 5.3 mg C L(-1). Excitation-emission matrix (EEM) spectroscopy and parallel factor analysis (PARAFAC) modelling showed urban pond DOM to be characterized by microbial-like and, less importantly, by terrestrial derived humic-like components. The relatively transparent, non-humic DOM in urban ponds was more similar to that found in open water, lake ecosystems than to rivers or wetlands. After irradiation equivalent to 1.7 days of natural solar radiation, DOC concentrations, on average, decreased by 38% and UV absorbance decreased by 25%. Irradiation decreased the relative abundances of terrestrial humic-like components and increased protein-like aspects of the DOM pool. These findings suggest that high internal production and/or prolonged exposure to sunlight exerts a distinct and significant influence on the chemistry of urban pond DOM, which likely reduces its chemical similarity with upstream sources. These properties of urban pond DOM may alter its biogeochemical role in these relatively novel aquatic ecosystems. PMID:24348908

McEnroe, Nicola A; Williams, Clayton J; Xenopoulos, Marguerite A; Porcal, Petr; Frost, Paul C

2013-01-01

388

Clean Graphene Electrodes on Organic Thin-Film Devices via Orthogonal Fluorinated Chemistry.  

PubMed

Graphene is a promising flexible, highly transparent, and elementally abundant electrode for organic electronics. Typical methods utilized to transfer large-area films of graphene synthesized by chemical vapor deposition on metal catalysts are not compatible with organic thin-films, limiting the integration of graphene into organic optoelectronic devices. This article describes a graphene transfer process onto chemically sensitive organic semiconductor thin-films. The process incorporates an elastomeric stamp with a fluorinated polymer release layer that can be removed, post-transfer, via a fluorinated solvent; neither fluorinated material adversely affects the organic semiconductor materials. We used Raman spectroscopy, atomic force microscopy, and scanning electron microscopy to show that chemical vapor deposition graphene can be successfully transferred without inducing defects in the graphene film. To demonstrate our transfer method's compatibility with organic semiconductors, we fabricate three classes of organic thin-film devices: graphene field effect transistors without additional cleaning processes, transparent organic light-emitting diodes, and transparent small-molecule organic photovoltaic devices. These experiments demonstrate the potential of hybrid graphene/organic devices in which graphene is deposited directly onto underlying organic thin-film structures. PMID:25774924

Beck, Jonathan H; Barton, Robert A; Cox, Marshall P; Alexandrou, Konstantinos; Petrone, Nicholas; Olivieri, Giorgia; Yang, Shyuan; Hone, James; Kymissis, Ioannis

2015-04-01

389

Determining the EDTA Content in a Consumer Shower Cleaner. An Introductory Chemistry Laboratory Experiment  

NASA Astrophysics Data System (ADS)

At Altoona College, Chemistry 11 is offered to students as a preparatory course for the University's Chemical Principles course, Chem 12. A relevant laboratory is a source of motivation for the students to learn the chemistry. One way of making the laboratory relevant is to analyze the chemical components of consumer products. Several new shower-cleaning products have been introduced, which advertise that cleaning the shower is no longer necessary. The cleaners work using a combination of surfactants, alcohols, and a chelating agent. The Web site of a popular shower cleaner lists EDTA (ethylenediamine tetraacetate ion) as the chelating agent. The classic EDTA/calcium complexometric titration can be used to determine the EDTA content of the cleaner. This article describes the experiment to determine the EDTA content in a shower-cleaning product.

Weigand, Willis A.

2000-10-01

390

Integrating Organic Matter Structure with Ecosystem Function using Advanced Analytical Chemistry Techniques  

NASA Astrophysics Data System (ADS)

Microorganisms are the primary transformers of organic matter in terrestrial and aquatic ecosystems. The structure of organic matter controls its bioavailability and researchers have long sought to link the chemical characteristics of the organic matter pool to its lability. To date this effort has been primarily attempted using low resolution descriptive characteristics (e.g. organic matter content, carbon to nitrogen ratio, aromaticity, etc .). However, recent progress in linking these two important ecosystem components has been advanced using advanced high resolution tools (e.g. nuclear magnetic resonance (NMR) spectroscopy, and mass spectroscopy (MS)-based techniques). A series of experiments will be presented that highlight the application of high resolution techniques in a variety of terrestrial and aquatic ecosystems with the focus on how these data explicitly provide the foundation for integrating organic matter structure into our concept of ecosystem function. The talk will highlight results from a series of experiments including: an MS-based metabolomics and fluorescence excitation emission matrix approach evaluating seasonal and vegetation based changes in dissolved organic matter (DOM) composition from arctic soils; Fourier transform ion cyclotron resonance (FTICR) MS and MS metabolomics analysis of DOM from three lakes in an alpine watershed; and the transformation of 13C labeled glucose track with NMR during a rewetting experiment from Colorado grassland soils. These data will be synthesized to illustrate how the application of advanced analytical techniques provides novel insight into our understanding of organic matter processing in a wide range of ecosystems.

Boot, C. M.

2012-12-01

391

Chemistry Notes.  

ERIC Educational Resources Information Center

Presents background information, laboratory procedures, classroom materials/activities, and experiments for chemistry. Topics include superheavy elements, polarizing power and chemistry of alkali metals, particulate carbon from combustion, tips for the chemistry laboratory, interesting/colorful experiments, behavior of bismuth (III) iodine, and…

School Science Review, 1982

1982-01-01

392

Intrinsic charge trapping in organic and polymeric semiconductors: a physical chemistry perspective  

SciTech Connect

We aim to understand the origins of intrinsic charge carrier traps in organic and polymeric semiconductor materials from a physical chemistry perspective. In crystalline organic semiconductors, we point out some of the inadequacies in the description of intrinsic charge traps using language and concepts developed for inorganic semiconductors. In ?-conjugated polymeric semiconductors, we suggest the presence of a two-tier electronic energy landscape, a bimodal majority landscape due to two dominant structural motifs and a minority electronic energy landscape from intrinsic charged defects. The bimodal majority electronic energy landscape results from a combination of amorphous domains and microcrystalline or liquid-crystalline domains. The minority tier of the electronic density of states is comprised of deep Coulomb traps embedded in the majority electronic energy landscape. This minority electronic energy landscape may dominate transport properties at low charge carrier densities, such as those expected for organic photovoltaic devices, while the bimodal majority electronic energy landscape becomes significant at high carrier densities, that is, in organic field effect transistors.

Zhu, Xiaoyang; Barbara, Paul F.; Kaake, Loren

2010-01-01

393

Molecular identification of organic compounds in atmospheric complex mixtures and relationship to atmospheric chemistry and sources.  

PubMed Central

This article describes a chemical characterization approach for complex organic compound mixtures associated with fine atmospheric particles of diameters less than 2.5 m (PM2.5). It relates molecular- and bulk-level chemical characteristics of the complex mixture to atmospheric chemistry and to emission sources. Overall, the analytical approach describes the organic complex mixtures in terms of a chemical mass balance (CMB). Here, the complex mixture is related to a bulk elemental measurement (total carbon) and is broken down systematically into functional groups and molecular compositions. The CMB and molecular-level information can be used to understand the sources of the atmospheric fine particles through conversion of chromatographic data and by incorporation into receptor-based CMB models. Once described and quantified within a mass balance framework, the chemical profiles for aerosol organic matter can be applied to existing air quality issues. Examples include understanding health effects of PM2.5 and defining and controlling key sources of anthropogenic fine particles. Overall, the organic aerosol compositional data provide chemical information needed for effective PM2.5 management. PMID:12634131

Mazurek, Monica A

2002-01-01

394

Chemistry of decomposition of freshwater wetland sedimentary organic material during ramped pyrolysis  

NASA Astrophysics Data System (ADS)

Ramped pyrolysis methodology, such as that used in the programmed-temperature pyrolysis/combustion system (PTP/CS), improves radiocarbon analysis of geologic materials devoid of authigenic carbonate compounds and with low concentrations of extractable authochthonous organic molecules. The approach has improved sediment chronology in organic-rich sediments proximal to Antarctic ice shelves (Rosenheim et al., 2008) and constrained the carbon sequestration potential of suspended sediments in the lower Mississippi River (Roe et al., in review). Although ramped pyrolysis allows for separation of sedimentary organic material based upon relative reactivity, chemical information (i.e. chemical composition of pyrolysis products) is lost during the in-line combustion of pyrolysis products. A first order approximation of ramped pyrolysis/combustion system CO2 evolution, employing a simple Gaussian decomposition routine, has been useful (Rosenheim et al., 2008), but improvements may be possible. First, without prior compound-specific extractions, the molecular composition of sedimentary organic matter is unknown and/or unidentifiable. Second, even if determined as constituents of sedimentary organic material, many organic compounds have unknown or variable decomposition temperatures. Third, mixtures of organic compounds may result in significant chemistry within the pyrolysis reactor, prior to introduction of oxygen along the flow path. Gaussian decomposition of the reaction rate may be too simple to fully explain the combination of these factors. To relate both the radiocarbon age over different temperature intervals and the pyrolysis reaction thermograph (temperature (°C) vs. CO2 evolved (?mol)) obtained from PTP/CS to chemical composition of sedimentary organic material, we present a modeling framework developed based upon the ramped pyrolysis decomposition of simple mixtures of organic compounds (i.e. cellulose, lignin, plant fatty acids, etc.) often found in sedimentary organic material to account for changes in thermograph shape. The decompositions will be compositionally verified by 13C NMR analysis of pyrolysis residues from interrupted reactions. This will allow for constraint of decomposition temperatures of individual compounds as well as chemical reactions between volatilized moieties in mixtures of these compounds. We will apply this framework with 13C NMR analysis of interrupted pyrolysis residues and radiocarbon data from PTP/CS analysis of sedimentary organic material from a freshwater marsh wetland in Barataria Bay, Louisiana. We expect to characterize the bulk chemical composition during pyrolysis and as well as diagenetic changes with depth. Most importantly, we expect to constrain the potential and the limitations of this modeling framework for application to other depositional environments.

Williams, E. K.; Rosenheim, B. E.

2011-12-01

395

Chemistry Notes  

ERIC Educational Resources Information Center

Described are eight chemistry experiments and demonstrations applicable to introductory chemistry courses. Activities include: measure of lattice enthalpy, Le Chatelier's principle, decarboxylation of soap, use of pocket calculators in pH measurement, and making nylon. (SL)

School Science Review, 1976

1976-01-01

396

Chemistry Notes.  

ERIC Educational Resources Information Center

Presents background information, laboratory procedures, classroom materials/activities, and chemistry experiments. Topics include sublimation, electronegativity, electrolysis, experimental aspects of strontianite, halide test, evaluation of present and future computer programs in chemistry, formula building, care of glass/saturated calomel…

School Science Review, 1983

1983-01-01

397

Ascorbic Acid as a Standard for Iodometric Titrations. An Analytical Experiment for General Chemistry  

NASA Astrophysics Data System (ADS)

Ascorbic acid is suggested as the weighable compound for the standardization of iodine solutions in an analytical experiment in general chemistry. The experiment involves an iodometric titration in which iodine reacts with ascorbic acid, oxidizing it to dehydroascorbic acid. The redox titration endpoint is determined by the first iodine excess that is complexed with starch, giving a deep blue-violet color. The results of the titration of iodine solution using ascorbic acid as a calibration standard were compared with the results acquired by the classic method using a standardized solution of sodium thiosulfate. The standardization of the iodine solution using ascorbic acid was accurate and precise, with the advantages of saving time and avoiding mistakes due to solution preparation. The colorless ascorbic acid solution gives a very clear and sharp titration end point with starch. It was shown by thermogravimetric analysis that ascorbic acid can be dried at 393 K for 2 h without decomposition. This experiment allows general chemistry students to perform an iodometric titration during a single laboratory period, determining with precision the content of vitamin C in pharmaceutical formulations.

Silva, Cesar R.; Simoni, Jose A.; Collins, Carol H.; Volpe, Pedro L. O.

1999-10-01

398

Aerosol and cloud chemistry of amines from CCS - reactivity experiments and numerical modeling  

NASA Astrophysics Data System (ADS)

Capturing CO2 from the exhaust of power plants using amine scrubbing is a common technology. Therefore, amines can be released during the carbon capture process. To investigate the tropospheric chemical fate of amines from CO2 capturing processes and their oxidation products, the impact of aqueous aerosol particles and cloud droplets on the amine chemistry has been considered. Aqueous phase reactivity experiments of NO3 radicals and ozone with relevant amines and their corresponding nitrosamines were performed. Furthermore, nitrosamine formation and nitrosamine photolysis was investigated during laboratory experiments. These experiments implicated that aqueous phase photolysis can be an effective sink for nitrosamines and that ozone is unreactive towards amines and nitrosamines. Multiphase phase oxidation schemes of amines, nitrosamines and amides were developed, coupled to the existing multiphase chemistry mechanism CAPRAM and built into the Lagrangian parcel model SPACCIM using published and newly measured data. As a result, both deliquescent particles and cloud droplets are important compartments for the multiphase processing of amines and their products. Amines can be readily oxidised by OH radicals in the gas and cloud phase during daytime summer conditions. However, amine oxidation is restricted during winter conditions with low photochemical activity leading to long lifetimes of amines. The importance of the gas and aqueous phase depends strongly on the partitioning of the different amines. Furthermore, the simulations revealed that the aqueous formation of nitrosamines in aerosol particles and could droplets is not a relevant process under tropospheric conditions.

Weller, Christian; Tilgner, Andreas; Herrmann, Hartmut

2013-04-01

399

Development and analysis of educational technologies for a blended organic chemistry course  

NASA Astrophysics Data System (ADS)

Blended courses incorporate elements of both face-to-face and online instruction. The extent to which blended courses are conducted online, and the proper role of the online components of blended courses, have been debated and may vary. What can be said in general, however, is that online tools for blended courses are typically culled together from a variety of sources, are often very large scale, and may present distractions for students that decrease their utility as teaching tools. Furthermore, large-scale educational technologies may not be amenable to rigorous, detailed study, limiting evaluation of their effectiveness. Small-scale educational technologies run from the instructor's own server have the potential to mitigate many of these issues. Such tools give the instructor or researcher direct access to all available data, facilitating detailed analysis of student use. Code modification is simple and rapid if errors arise, since code is stored where the instructor can easily access it. Finally, the design of a small-scale tool can target a very specific application. With these ideas in mind, this work describes several projects aimed at exploring the use of small-scale, web-based software in a blended organic chemistry course. A number of activities were developed and evaluated using the Student Assessment of Learning Gains survey, and data from the activities were analyzed using quantitative methods of statistics and social network analysis methods. Findings from this work suggest that small-scale educational technologies provide significant learning benefits for students of organic chemistry---with the important caveat that instructors must offer appropriate levels of technical and pedagogical support for students. Most notably, students reported significant learning gains from activities that included collaborative learning supported by novel online tools. For the particular context of organic chemistry, which has a unique semantic language (Lewis structures), the incorporation of shared video was a novel but important element of these activities. In fields for which mere text would not provide enough information in communications between students, video offers an appealing medium for student-student interaction.

Evans, Michael James

400

Global tropospheric experiment at the Hong Kong Atmosphere Chemistry Measurement Station  

NASA Technical Reports Server (NTRS)

The major activities of the Global Tropospheric Experiment at the Hong Kong Atmospheric Chemistry Measurement Station are presented for the period 1 January - 31 December 1995. Activities included data analysis, reduction, and archiving of atmospheric measurements and sampling. Sampling included O3, CO, SO2, NO, TSP, RSP, and ozone column density. A data archive was created for the surface meteorological data. Exploratory data analysis was performed, including examination of time series, frequency distributions, diurnal variations and correlation. The major results have been or will be published in scientific journals as well as presented at conferences/workshops. Abstracts are attached.

Carroll, Mary Ann; Wang, Tao

1995-01-01

401

Introducing ethics to chemistry students in a "Research Experiences for Undergraduates" (REU) program.  

PubMed

A three-day ethics seminar introduced ethics to undergraduate environmental chemistry students in the Research Experiences for Undergraduates (REU) program. The seminar helped students become sensitive to and understand the ethical and values dimensions of their work as researchers. It utilized a variety of resources to supplement lectures and class discussion on a variety of issues. Students learned about the relevance of ethics to research, skills in moral reasoning, and the array of ethical issues facing various aspects of scientific research. © 2015 by The International Union of Biochemistry and Molecular Biology, 43(2):76-80, 2015. PMID:25727066

Hanson, Mark J

2015-03-01

402

Adsorption of amino acids and nucleic acid bases onto minerals: a few suggestions for prebiotic chemistry experiments  

NASA Astrophysics Data System (ADS)

Amino acids and nucleic acid bases are very important for the living organisms. Thus, their protection from decomposition, selection, pre-concentration and formation of biopolymers are important issues for understanding the origin of life on the Earth. Minerals could have played all of these roles. This paper discusses several aspects involving the adsorption of amino acids and nucleic acid bases onto minerals under conditions that could have been found on the prebiotic Earth; in particular, we recommend the use of minerals, amino acids, nucleic acid bases and seawater ions in prebiotic chemistry experiments. Several experiments involving amino acids, nucleic acid bases, minerals and seawater ions are also suggested, including: (a) using well-characterized minerals and the standardization of the mineral synthesis methods; (b) using primary chondrite minerals (olivine, pyroxene, etc.) and clays modified with metals (Cu, Fe, Ni, Mo, Zn, etc.); (c) determination of the possible products of decomposition due to interactions of amino acids and nucleic acid bases with minerals; (d) using minerals with more organophilic characteristics; (e) using seawaters with different concentrations of ions (i.e. Na+, Ca2+, Mg2+, SO4 2- and Cl-) (f) using non-protein amino acids (AIB, ?-ABA, ?-ABA, ?-ABA and ?-Ala and g) using nucleic acid bases other than adenine, thymine, uracil and cytosine. These experiments could be useful to clarify the role played by minerals in the origin of life on the Earth.

Zaia, Dimas A. M.

2012-10-01

403

Evaluation of modeled cloud chemistry mechanism against laboratory irradiation experiments: The HxOy/iron/carboxylic acid chemical system  

NASA Astrophysics Data System (ADS)

Currently, cloud chemistry models are including more detailed and explicit multiphase mechanisms based on laboratory experiments that determine such values as kinetic constants, stability constants of complexes and hydration constants. However, these models are still subject to many uncertainties related to the aqueous chemical mechanism they used. Particularly, the role of oxidants such as iron and hydrogen peroxide in the oxidative capacity of the cloud aqueous phase has typically never been validated against laboratory experimental data. To fill this gap, we adapted the M2C2 model (Model of Multiphase Cloud Chemistry) to simulate irradiation experiments on synthetic aqueous solutions under controlled conditions (e.g., pH, temperature, light intensity) and for actual cloud water samples. Various chemical compounds that purportedly contribute to the oxidative budget in cloud water (i.e., iron, oxidants, such as hydrogen peroxide: H2O2) were considered. Organic compounds (oxalic, formic and acetic acids) were taken into account as target species because they have the potential to form iron complexes and are good indicators of the oxidative capacity of the cloud aqueous phase via their oxidation in this medium. The range of concentrations for all of the chemical compounds evaluated was representative of in situ measurements. Numerical outputs were compared with experimental data that consisted of a time evolution of the concentrations of the target species. The chemical mechanism in the model describing the “oxidative engine” of the HxOy/iron (HxOy = H2O2, HO2rad /O2rad - and HOrad ) chemical system was consistent with laboratory measurements. Thus, the degradation of the carboxylic acids evaluated was closely reproduced by the model. However, photolysis of the Fe(C2O4)+ complex needs to be considered in cloud chemistry models for polluted conditions (i.e., acidic pH) to correctly reproduce oxalic acid degradation. We also show that iron and formic acid lead to a stable complex whose photoreactivity has currently not been investigated. The updated aqueous chemical mechanism was compared with data from irradiation experiments using natural cloud water. The new reactions considered in the model (i.e., iron complex formation with oxalic and formic acids) correctly reproduced the experimental observations.

Long, Yoann; Charbouillot, Tiffany; Brigante, Marcello; Mailhot, Gilles; Delort, Anne-Marie; Chaumerliac, Nadine; Deguillaume, Laurent

2013-10-01

404

Modular thiol-ene chemistry approach towards mesoporous silica monoliths with organically modified pore walls.  

PubMed

The surface modification of mesoporous silica monoliths through thiol-ene chemistry is reported. First, mesoporous silica monoliths with vinyl, allyl, and thiol groups were synthesized through a sol-gel hydrolysis-polycondensation reaction from tetramethyl orthosilicate (TMOS) and vinyltriethoxysilane, allyltriethoxysilane, and (3-mercaptopropyl)trimethoxysilane, respectively. By variation of the molar ratio of the comonomers TMOS and functional silane, mesoporous silica objects containing different amounts of vinyl, allyl, and thiol groups were obtained. These intermediates can subsequently be derivatized through radical photoaddition reactions either with a thiol or an olefin, depending on the initial pore wall functionality, to yield silica monoliths with different pore-wall chemistries. Nitrogen sorption, small-angle X-ray scattering, solid-state NMR spectroscopy, elemental analysis, thermogravimetric analysis, and redox titration demonstrate that the synthetic pathway influences the morphology and pore characteristics of the resulting monoliths and also plays a significant role in the efficiency of functionalization. Moreover, the different reactivity of the vinyl and allyl groups on the pore wall affects the addition reaction, and hence, the degree of the pore-wall functionalization. This report demonstrates that thiol-ene photoaddition reactions are a versatile platform for the generation of a large variety of organically modified silica monoliths with different pore surfaces. PMID:25335454

Göbel, Ronald; Hesemann, Peter; Friedrich, Alwin; Rothe, Regina; Schlaad, Helmut; Taubert, Andreas

2014-12-22

405

Fostering expert inquiry skills and beliefs about chemistry through the MORE laboratory experience  

NASA Astrophysics Data System (ADS)

Typical college science instruction fails to promote an accurate view of science as a discipline and a practice. This is likely due to the fact that the experiences of students in the classroom are very different from the actions and thought processes of scientists. Thus, students often leave the classroom experience with poor inquiry skills and naive beliefs about scientific practice. In order to bridge the gap between the typical classroom experience and expert practice, the MORE Project laboratory curriculum was developed to accompany the general chemistry course at the University of California at Berkeley. The framework guiding the curriculum development considered findings from educational and cognitive science research. The three components of the framework are: (a) exploration of concepts through authentic scientific inquiry; (b) promotion of metacognition; and (c) support for guided discovery. The curriculum provides students with a cognitive model of expert research, the MORE (Model-Observe-Reflect-Explain) Cycle, to encourage students to explore conceptually-rich systems through authentic research opportunities, such as designing experiments and refining explanatory models. By embedding the MORE structure into the laboratory curriculum, we provide students with a model for how scientists think through the inquiry process. In order to assess the impact of the MORE Project learning environment, it was implemented in two sections concurrent with the traditional laboratory experience. Various instruments were administered to determine any differences between the test and control groups with regards to attitudes towards chemistry, conceptual understanding, inquiry skills, and beliefs about scientific practice. Based on the analyses, students experiencing the MORE classroom achieved significant gains in all areas compared with students enrolled in the more traditional laboratory class. Specifically, students in the MORE class (a) recognized the complex, dynamic processes typical of scientific practice; (b) developed more sophisticated inquiry skills; and (c) practiced modeling and reflection in the laboratory.

Tien, Lydia Tsing

406

Synthesis of Well-Defined Copper "N"-Heterocyclic Carbene Complexes and Their Use as Catalysts for a "Click Reaction": A Multistep Experiment that Emphasizes the Role of Catalysis in Green Chemistry  

ERIC Educational Resources Information Center

A multistep experiment for an advanced synthesis lab course that incorporates topics in organic-inorganic synthesis and catalysis and highlights green chemistry principles was developed. Students synthesized two "N"-heterocyclic carbene ligands, used them to prepare two well-defined copper(I) complexes and subsequently utilized the complexes as…

Ison, Elon A.; Ison, Ana

2012-01-01

407

Distributed Pore Chemistry in Porous Organic Polymers in Tissue Culture Flasks  

NASA Technical Reports Server (NTRS)

A method for making a biocompatible polymer article using a uniform atomic oxygen treatment is disclose. The substrate may be subsequently optionally grated with a compatibilizing compound. Compatibilizing compounds may include proteins, phosphorylcholine groups, platelet adhesion preventing polymers, albumin adhesion promoters, and the like. The compatibilized substrate may also have a living cell layer adhered thereto. The atomic oxygen is preferably produced by a flowing afterglow microwave discharge, wherein the substrate resides in a sidearm out of the plasma. Also, methods for culturing cells for various purposes using the various membranes are disclosed as well. Also disclosed are porous organic polymers having a distributed pore chemistry (DPC) comprising hydrophilic and hydrophobic regions, and a method for making the DPC by exposing the polymer to atomic oxygen wherein the rate of hydrophilization is greater than the rate of mass loss.

Koontz, Steven L. (Inventor)

1999-01-01

408

Synthesis and Hydrogenation of Disubstituted Chalcones: A Guided-Inquiry Organic Chemistry Project  

ERIC Educational Resources Information Center

Guided-inquiry experiments offer the same opportunities to participate in the process of science as classical organic qualitative analysis used to do. This three-week guided-inquiry project involves an aldol-dehydration synthesis of a chalcone chosen from a set of nine, followed by a catalytic transfer hydrogenation reaction using ammonium formate…

Mohrig, Jerry R.; Hammond, Christina Noring; Schatz, Paul F.; Davidson, Tammy A.

2009-01-01

409

Green Chemistry Decision-Making in an Upper-Level Undergraduate Organic Laboratory  

ERIC Educational Resources Information Center

A self-directed independent synthesis experiment was developed for a third-year undergraduate organic laboratory. Students were provided with the CAS numbers of starting and target compounds and devised a synthetic plan to be executed over two 4.5 h laboratory periods. They consulted the primary literature in order to develop and carry out an…

Edgar, Landon J. G.; Koroluk, Katherine J.; Golmakani, Mehrnaz; Dicks, Andrew P.

2014-01-01

410

Coupling Molecular Modeling to the Traditional "IR-ID" Exercise in the Introductory Organic Chemistry Laboratory  

ERIC Educational Resources Information Center

This exercise integrates the infrared unknown identification ("IR-ID") experiment common to most organic laboratory syllabi with computer molecular modeling. In this modification students are still required to identify unknown compounds from their IR spectra, but must additionally match some of the absorptions with computed frequencies they…

Stokes-Huby, Heather; Vitale, Dale E.

2007-01-01

411

Secondary organic aerosol formation from aqueous chemistry of glyoxal, methylglyoxal, and glycolaldehyde in atmospheric waters: Chemical insights and kinetic model studies  

NASA Astrophysics Data System (ADS)

Aqueous chemistry in clouds, fog and aerosol water is now considered an important source of secondary organic aerosol (SOA). Modeling studies confirm that the underlying chemistry is kinetically favorable. Laboratory studies have begun to validate and refine the aqueous chemical mechanisms. Field observations, such as the atmospheric abundance of oxalate, ubiquitous presence of high molecular weight or humic-like substances (HULIS), high ambient O/C ratios, and correlations between SOA and aerosol liquid water content provide atmospheric evidence for SOA formation through aqueous chemistry. In the aqueous phase, small and volatile (C2-C3) but water soluble organic compounds undergo radical (photooxidation) and non-radical (acid/base catalysis) reactions, or reactions with inorganic constituents (sulfate, nitrate or ammonia) to form low volatility products including organic acids, organic-inorganic complexes and oligomers. These products are expected to remain at least in part in the particle phase after water evaporation, forming SOA. While not traditionally considered to be SOA precursors, atmospherically abundant and water soluble organic compounds like glyoxal (C2), methylglyoxal (C3) and glycolaldehyde (C2) have great potential to form SOA via aqueous chemistry. This paper presents a unified reaction mechanism and full kinetic model for the aqueous-phase reaction of glyoxal, methylglyoxal, glycolaldehyde, pyruvic acid and acetic acid with OH radical and validates this mechanism, in part, with laboratory experiments. At cloud relevant concentrations (~1E-6 M), the major product is oxalic acid and formation is well predicted by the previous cloud model (Lim et al., 2005). As concentrations increase radical-radical reactions become increasingly important and yield higher molecular weight products. The full kinetic model suggests that SOA formed in aerosol water (where organic concentrations are > 1 M) is comprised of high molecular weight multifunctional compounds. Atmospheric aqueous chemistry can potentially explain the atmospheric formation of oxalate, oligomers and HULIS. The insights gained from the full kinetic model can be used to aid the development of simplified modules for incorporation of this SOA formation process into chemical transport models.

Lim, Y. B.; Tan, Y.; Altieri, K. E.; Perri, M. J.; Carlton, A. G.; Seitzinger, S.; Turpin, B. J.

2010-12-01

412

Preliminary analysis of LDEF instrument A0187-1: Chemistry of Micrometeoroids Experiment  

NASA Technical Reports Server (NTRS)

The Chemistry of Micrometeoroids Experiment (CME) exposed approximately 0.8 sq. m of gold on the Long Duration Exposure Facility's (LDEF's) trailing edge (location A03) and approximately 1.1 sq. m of aluminum in the forward-facing A11 location. The most significant results to date relate to the discovery of unmelted pyroxene and olivine fragments associated with natural cosmic dust impacts. The latter are sufficiently large for detailed phase studies, and they serve to demonstrate that recovery of unmelted dust fragments is a realistic prospect for further dust experiments that will employ more advanced collector media. We also discovered that man-made debris impacts occur on the LDEF's trailing edge with substantially higher frequency than expected, suggesting that orbital debris in highly elliptical orbits may have been somewhat underestimated.

Hoerz, Friedrich; Bernhard, Ronald P.; Warren, Jack; See, Thomas H.; Brownlee, Donald E.; Laurance, Mark R.; Messenger, Scott; Peterson, Robert B.

1992-01-01

413

Major Successes of Theory-and-Experiment-Combined Studies in Surface Chemistry and Heterogeneous Catalysis.  

SciTech Connect

Experimental discoveries followed by theoretical interpretations that pave the way of further advances by experimentalists is a developing pattern in modern surface chemistry and catalysis. The revolution of modern surface science started with the development of surface-sensitive techniques such as LEED, XPS, AES, ISS and SIMS, in which the close collaboration between experimentalists and theorists led to the quantitative determination of surface structure and composition. The experimental discovery of the chemical activity of surface defects and the trends in the reactivity of transitional metals followed by the explanations from the theoretical studies led to the molecular level understanding of active sites in catalysis. The molecular level knowledge, in turn, provided a guide for experiments to search for new generation of catalysts. These and many other examples of successes in experiment-and-theory-combined studies demonstrate the importance of the collaboration between experimentalists and theorists in the development of modern surface science.

Somorjai, Gabor A.; Li, Yimin

2009-11-21

414

In situ experiment of ontogenetic variability in the otolith chemistry of Stegastes partitus  

Microsoft Academic Search

Otolith chemistry can be used to assess pelagic larval fish connectivity by comparing spatially variable otolith edge chemistry (corresponding to the site of collection) to otolith core chemistry (corresponding to the site of hatching). However, because the otolith’s edge and core represent different life stages, the deposition of elements may differ, thus complicating direct comparisons of edge and core chemistry

P. M. Chittaro; J. D. Hogan; J. Gagnon; B. J. Fryer; P. F. Sale

2006-01-01

415

Observations of peroxyacetyl nitrate (PAN) in the upper troposphere by the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS)  

NASA Astrophysics Data System (ADS)

Peroxyacetyl nitrate (CH3CO·O2NO2, abbreviated as PAN) is a trace molecular species present in the troposphere and lower stratosphere due primarily to pollution from fuel combustion and the pyrogenic outflows from biomass burning. In the lower troposphere, PAN has a relatively short life-time and is principally destroyed within a few hours through thermolysis, but it can act as a reservoir and carrier of NOx in the colder temperatures of the upper troposphere where UV photolysis becomes the dominant loss mechanism. Pyroconvective updrafts from large biomass burning events can inject PAN into the upper troposphere and lower stratosphere (UTLS), providing a means for the long-range transport of NOx. Given the extended lifetimes at these higher altitudes, PAN is readily detectable via satellite remote sensing. A new PAN data product is now available for the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) Version 3.0 data set. We report measurements of PAN in Boreal biomass burning plumes recorded during the Quantifying the impact of BOReal forest fires on Tropospheric oxidants over the Atlantic using Aircraft and Satellites (BORTAS) campaign. The retrieval method employed and errors analysis are described in full detail. The retrieved volume mixing ratio (VMR) profiles are compared to coincident measurements made by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument on the European Space Agency (ESA) ENVIronmental SATellite (ENVISAT). Three ACE-FTS occultations containing measurements of Boreal biomass burning outflows, recorded during BORTAS, were identified as having coincident measurements with MIPAS. In each case, the MIPAS measurements demonstrated good agreement with the ACE-FTS VMR profiles for PAN. The ACE-FTS PAN data set is used to obtain zonal mean distributions of seasonal averages from ~5 to 20 km. A strong seasonality is clearly observed for PAN concentrations in the global UTLS. Since the principal source of PAN in the UTLS is due to lofted biomass burning emissions from the pyroconvective updrafts created by large fires, the observed seasonality in enhanced PAN coincides with fire activity in different geographical regions throughout the year. This work is part of an in-depth investigation that is being conducted in an effort to study the aging and chemical evolution of biomass burning emissions in the UTLS by remote, space-borne measurements made by ACE-FTS to further our understanding of the impact of pyrogenic emissions on atmospheric chemistry. Included in this study will be the addition of new, pyrogenic, volatile organic hydrocarbons (VOCs) and oxygenated volatile organic compounds (OVOCs) to expand upon the already extensive suite of molecules retrieved by ACE-FTS to aid in elucidating biomass burning plume chemistry in the free troposphere.

Tereszchuk, K. A.; Moore, D. P.; Harrison, J. J.; Boone, C. D.; Park, M.; Remedios, J. J.; Randel, W. J.; Bernath, P. F.

2013-01-01

416

Microcomputer-Analyzed Initial Rate Kinetics of the Benzene-Enhanced Unfolding of Myoglobin: A Biophysical Chemistry Experiment.  

ERIC Educational Resources Information Center

Describes a biophysical chemistry experiment that introduces students to globular protein conformation and microcomputer analysis of initial rate data for the unfolding of proteins. Presents background, materials needed and methodology. Uses a visible spectrometer for analysis. Lists educational benefits derived from the experiment. (ML)

Schuh, Merlyn D.

1988-01-01

417

Characterization of High Explosives and Other Energetic Compounds by Computational Chemistry and Molecular Modeling: Experiments for Undergraduate Curriculum  

ERIC Educational Resources Information Center

Experiments suited for the undergraduate instructional laboratory in which the heats of formation of several aliphatic and aromatic compounds are calculated, are described. The experiments could be used to introduce students to commercially available computational chemistry and its thermodynamics, while assess and compare the energy content of…

Bumpus, John A.; Lewis, Anne; Stotts, Corey; Cramer, Christopher J.

2007-01-01

418

Electrochemistry of (Dihapto-Buckminster-Fullerene) Pentacarbonyl Tungsten(0): An Experiment for the Inorganic Chemistry Laboratory, Part III  

ERIC Educational Resources Information Center

Cyclic voltammetry experiments on [60]fullerene, (C[subscript 60]), and (dihapto-[60]fullerene) pentacarbonyl tungsten(0), ([eta][superscript 2]-C[subscript 60])W(CO)[subscript 5], constitute an educational experiment for the inorganic chemistry laboratory with a primary objective to teach the chemical interpretation of a voltammogram, in…

Igartua-Nieves, Elvin; Ocasio-Delgado, Yessenia; Rivera-Pagan, Jose; Cortes-Figueroa, Jose E.

2007-01-01

419

Determination of Spin-Lattice Relaxation of Time Using (Super 13)C NMR: An Undergraduate Physical Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

An experiment designed for the physical chemistry laboratory where (super 13)C NMR is applied to determine the spin-lattice relaxation time for carbon atoms in n-hexanol is proposed. It is concluded that students learn the principles and concepts of NMR spectroscopy as well as dynamic NMR experiments.

Gasyna, Zbigniew L.; Jurkiewicz, Antoni

2004-01-01

420

Organic geochemistry and pore water chemistry of sediments from Mangrove Lake, Bermuda  

USGS Publications Warehouse

Mangrove Lake, Bermuda, is a small coastal, brackish-water lake that has accumulated 14 m of banded, gelatinous, sapropelic sediments in less than 104 yr. Stratigraphic evidence indicates that Mangrove Lake's sedimentary environment has undergone three major depositional changes (peat, freshwater gel, brackish-water gel) as a result of sea level changes. The deposits were examined geochemically in an effort to delineate sedimentological and diagenetic changes. Gas and pore water studies include measurements of sulfides, ammonia, methane, nitrogen gas, calcium, magnesium, chloride, alkalinity, and pH. Results indicate that sulfate reduction is complete, and some evidence is presented for bacterial denitrification and metal sulfide precipitation. The organic-rich sapropel is predominantly algal in origin, composed mostly of carbohydrates and insoluble macromolecular organic matter called humin with minor amounts of proteins, lipids, and humic acids. Carbohydrates and proteins undergo hydrolysis with depth in the marine sapropel but tend to be preserved in the freshwater sapropel. The humin, which has a predominantly aliphatic structure, increases linearly with depth and composes the greatest fraction of the organic matter. Humic acids are minor components and are more like polysaccharides than typical marine humic acids. Fatty acid distributions reveal that the lipids are of an algal and/or terrestrial plant source. Normal alkanes with a total concentration of 75 ppm exhibit two distribution maxima. One is centered about n-C22 with no odd/even predominance, suggestive of a degraded algal source. The other is centered at n-C31 with a distinct odd/even predominance indicative of a vascular plant origin. Stratigraphic changes in the sediment correlate to observed changes in the gas and pore water chemistry and the organic geochemistry. ?? 1982.

Hatcher, P.G.; Simoneit, B.R.T.; MacKenzie, F.T.; Neumann, A.C.; Thorstenson, D.C.; Gerchakov, S.M.

1982-01-01

421

Field Characterization of the Mineralogy and Organic Chemistry of Carbonates from the 2010 Arctic Mars Analog Svalbard Expedition by Evolved Gas Analysis  

NASA Astrophysics Data System (ADS)

Carbonate data show that evolved gas analyses similar to those planned for the MSL SAM instrument suite can give constraints on sample organic chemistry, organic matter-mineral associations, and volatile-bearing minerals present at minor abundances.

McAdam, A. C.; Ten Kate, I. L.; Stern, J. C.; Mahaffy, P. R.; Blake, D. F.; Morris, R. V.; Steele, A.; Amundson, H. E. F.; Amase 2010 Team

2011-03-01

422

Organic Chemistry II Jasperse Acid-Base Practice Problems A. Rank the basicity of the following sets: Multiple Variable Problems  

E-print Network

1 Organic Chemistry II Jasperse Acid-Base Practice Problems A. Rank the basicity of the following more basic Carbonyl withdrawer makes less basic #12;2 B. Rank the acidity of the following sets will extract from ether into neutral water? b. Which will extract from ether into basic (NaOH) water? c. Which

Jasperse, Craig P.

423

Organic Chemistry II Jasperse Acid-Base Practice Problems A. Rank the basicity of the following sets: Multiple Variable Problems  

E-print Network

1 Organic Chemistry II Jasperse Acid-Base Practice Problems A. Rank the basicity of the following2ONa PhCO2Na methanol O O O OH NHNa ONa O OHONa NH O O OHO #12;2 B. Rank the acidity: a. Which will extract from ether into neutral water? b. Which will extract from ether into basic (Na

Jasperse, Craig P.

424

COMPUTATIONAL CHEMISTRY METHOD FOR PREDICTING VAPOR PRESSURES AND ACTIVITY COEFFICIENTS OF POLAR ORGANIC OXYGENATES IN PM2.5  

EPA Science Inventory

Parameterizations of interactions of polar multifunctional organic oxygenates in PM2.5 must be included in aerosol chemistry models for evaluating control strategies for reducing ambient concentrations of PM2.5 compounds. Vapor pressures and activity coefficients of these compo...

425

Organic Chemistry I Jasperse Newman Projections and Cyclohexane Chairs. Steps. Steps for processing a di-substituted cyclohexane chair  

E-print Network

1 Organic Chemistry I Jasperse Newman Projections and Cyclohexane Chairs. Steps. Steps whether that is cis or trans Steps for Drawing the Best Newman projection Newman projection, with three sticks on the "back" carbon and three on the "front". Have a stick up

Jasperse, Craig P.

426

Gender Fair Efficacy of Concept Mapping Tests in Identifying Students' Difficulties in High School Organic Chemistry  

ERIC Educational Resources Information Center

In view of the perceived difficulty of organic chemistry unit for high schools students, this study examined the usefulness of concept mapping as a testing device to assess students' difficulty in the select areas. Since many tests used for identifying students misconceptions and difficulties in school subjects are observed to favour one or…

Gafoor, Kunnathodi Abdul; Shilna, V.

2014-01-01

427

Development and Assessment of a Diagnostic Tool to Identify Organic Chemistry Students' Alternative Conceptions Related to Acid Strength  

ERIC Educational Resources Information Center

The central goal of this study was to create a new diagnostic tool to identify organic chemistry students' alternative conceptions related to acid strength. Twenty years of research on secondary and college students' conceptions about acids and bases has shown that these important concepts are difficult for students to apply to qualitative problem…

McClary, LaKeisha M.; Bretz, Stacey Lowery

2012-01-01

428

PAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Ruthenium half-sandwich complexes as protein kinase inhibitors  

E-print Network

PAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Ruthenium half-sandwich complexes on the web 20th March 2007 DOI: 10.1039/b700433h A general route to ruthenium pyridocarbazole half is replaced by a ruthenium fragment. Although structurally related, these new scaffolds turned out to possess

Meggers, Eric

429

The Cyclohexanol Cycle and Synthesis of Nylon 6,6: Green Chemistry in the Undergraduate Organic Laboratory  

ERIC Educational Resources Information Center

A one-term synthesis project that incorporates many of the principles of green chemistry is presented for the undergraduate organic laboratory. In this multistep scheme of reactions, students react, recycle, and ultimately convert cyclohexanol to nylon 6,6. The individual reactions in the project employ environmentally friendly methodologies, and…

Dintzner, Matthew R.; Kinzie, Charles R.; Pulkrabek, Kimberly; Arena, Anthony F.

2012-01-01

430

Tetraglyme Trap for the Determination of Volatile Organic Compounds in Urban Air: Projects for Undergraduate Analytical Chemistry  

ERIC Educational Resources Information Center

The differences in the levels of volatile organic compounds (VOCs), in the ambient air from the two urban locations, were studied by the undergraduate analytical chemistry students. Tetraglyme is very widely used due to its simplicity and its potential for use to investigate VOCs in ambient and indoor air employing a purge-and-trap concentrator…

Hope, Wilbert W.; Johnson, Clyde; Johnson, Leon P.

2004-01-01

431

Validating the Use of Concept-Mapping as a Diagnostic Assessment Tool in Organic Chemistry: Implications for Teaching  

ERIC Educational Resources Information Center

Science, Technology, Engineering, and Mathematics (STEM) education has become a key focus in the U.S. government's public education agenda. Many STEM degrees require the successful completion of undergraduate introductory organic chemistry (O-Chem), which is notorious for its difficulty and high attrition rate. Concept Maps (CM) have been used as…

Lopez, Enrique; Kim, Jennifer; Nandagopal, Kiruthiga; Cardin, Nate; Shavelson, Richard J.; Penn, John H.

2011-01-01

432

PAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Synthesis and anti-HIV activity of conformationally restricted bicyclic  

E-print Network

(TDF) and emtricitabine (FTC) have been approved by the FDA as anti-HIV drugs.2 HoweverPAPER www.rsc.org/obc | Organic & Biomolecular Chemistry Synthesis and anti-HIV activity (ddI) and 22o may explain the potent anti-HIV activity. Introduction Despite prodigious efforts

Theodorakis, Emmanuel

433

Analytical chemistry of the persistent organic pollutants identified in the Stockholm Convention: A review.  

PubMed

Persistent organic pollutants (POPs) are major environmental concern due to their persistence, long-range transportability, bio-accumulation and potentially adverse effects on living organisms. Analytical chemistry plays an essential role in the measurement of POPs and provides important information on their distribution and environmental transformations. Much effort has been devoted during the last two decades to the development of faster, safer, more reliable and more sensitive analytical techniques for these pollutants. Since the Stockholm Convention (SC) on POPs was adopted 12 years ago, analytical methods have been extensively developed. This review article introduces recent analytical techniques and applications for the determination of POPs in environmental and biota samples, and summarizes the extraction, separation and instrumental analyses of the halogenated POPs. Also, this review covers important aspects for the analyses of SC POPs (e.g. lipid determination and quality assurance/quality control (QA/QC)), and finally discusses future trends for improving the POPs analyses and for potential new POPs. PMID:23870403

Xu, Weiguang; Wang, Xian; Cai, Zongwei

2013-08-01

434

Chemistry Is Fun.  

ERIC Educational Resources Information Center

Encouraging scientific thinking through open-ended experiments, allowing students access to common chemical instrumentation, and introduction to laboratory techniques are goals of a high school science laboratory program. Course content (general, inorganic, and organic chemistry), limitations, and course evaluation are discussed. (Author/JN)

Yaniv, D; And Others

1982-01-01

435

Reaction Mechanisms for the Limited Reversibility of Li-O2 Chemistry in Organic Carbonate Electrolytes  

SciTech Connect

The Li-O2 chemistry in nonaqueous carbonate electrolytes and the underneath reason of its limited reversibility was exhaustively investigated. The discharge products collected from the air cathode in a Li-O2 battery at different depth of discharge (DOD) were systematically analyzed with X-ray diffraction. It is revealed that, independent of the discharge depth, lithium alkylcarbonate (either lithium propylenedicarbonate - LPDC, or lithium ethylenedicarbonate - LEDC, with other related derivatives) and lithium carbonate (Li2CO3) are always the main products, obviously originated from the electrolyte solvents propylene carbonate (PC) and ethylene carbonate (EC). These lithium alkylcarbonates are obviously generated from the single-electron reductive decomposition of the corresponding carbonate solvents initiated by the attack of superoxide radical anions. On the other hand, neither lithium peroxide (Li2O2) nor lithium oxide (Li2O) is detected. More significantly, from in situ gas chromatography/mass spectroscopy it is found that Li2CO3 and Li2O cannot be oxidized even when charged up to 4.6 V vs. Li/Li+, while LPDC, LEDC and Li2O2 are readily able to, with CO2 and CO released with the re-oxidation of LPDC and LEDC. It is therefore concluded that the quasi-reversibility of Li-O2 chemistry observed hitherto in an organic carbonate-based electrolyte is actually reliant on the formation of lithium alkylcarbonates through the reductive decomposition of carbonate solvents during discharge process and the subsequent oxidation of these same alkylcarbonates during charge process. It is the poor oxidizability of these alkylcarbonate species that constitutes the obstruction to an ideal rechargeable Li-O2 battery.

Xu, Wu; Xu, Kang; Viswanathan, Vilayanur V.; Towne, Silas A.; Hardy, John S.; Xiao, Jie; Nie, Zimin; Hu, Dehong; Wang, Deyu; Zhang, Jiguang

2011-11-15

436

Doing Chemistry  

NSDL National Science Digital Library

This website includes over 150 chemistry experiments in the following areas: Atomic Structure, Bonding, Chemical Reactions, Colligative Properties, Condensed States, Electrochemistry, Equilibrium Gases, Instrumentation, Limiting Reactant and more.

Brooks, David W.

437

Quantum Chemistry in Nanoscale Environments: Insights on Surface-Enhanced Raman Scattering and Organic Photovoltaics  

NASA Astrophysics Data System (ADS)

The understanding of molecular effects in nanoscale environments is becoming increasingly relevant for various emerging fields. These include spectroscopy for molecular identification as well as in finding molecules for energy harvesting. Theoretical quantum chemistry has been increasingly useful to address these phenomena to yield an understanding of these effects. In the first part of this dissertation, we study the chemical effect of surface-enhanced Raman scattering (SERS). We use quantum chemistry simulations to study the metal-molecule interactions present in these systems. We find that the excitations that provide a chemical enhancement contain a mixed contribution from the metal and the molecule. Moreover, using atomistic studies we propose an additional source of enhancement, where a transition metal dopant surface could provide an additional enhancement. We also develop methods to study the electrostatic effects of molecules in metallic environments. We study the importance of image-charge effects, as well as field-bias to molecules interacting with perfect conductors. The atomistic modeling and the electrostatic approximation enable us to study the effects of the metal interacting with the molecule in a complementary fashion, which provides a better understanding of the complex effects present in SERS. In the second part of this dissertation, we present the Harvard Clean Energy Project, a high-throughput approach for a large-scale computational screening and design of organic photovoltaic materials. We create molecular libraries to search for candidates structures and use quantum chemistry, machine learning and cheminformatics methods to characterize these systems and find structure-property relations. The scale of this study requires an equally large computational resource. We rely on distributed volunteer computing to obtain these properties. In the third part of this dissertation we present our work related to the acceleration of electronic structure methods using graphics processing units. This hardware represents a change of paradigm with respect to the typical CPU device architectures. We accelerate the resolution-of-the-identity Moller-Plesset second-order perturbation theory algorithm using graphics cards. We also provide detailed tools to address memory and single-precision issues that these cards often present.

Olivares-Amaya, Roberto

438

Patterning Self-Assembled Monolayers on Gold: Green Materials Chemistry in the Teaching Laboratory  

ERIC Educational Resources Information Center

An experiment demonstrating self-assembled monolayer (SAM) chemistry, organic thin-film patterning and the use of molecular functionality to control macroscopic properties is described. Several important green chemistry principles are introduced.

McFarland, Adam D.; Huffman, Lauren M.; Parent, Kathryn, E.; Hutchison, James E.; Thompson, John E.

2004-01-01

439

The Molecular Modeling Workbook for Organic Chemistry (by Warren J. Hehre, Alan J. Shusterman, and Janet E. Nelson)  

NASA Astrophysics Data System (ADS)

Wavefunction, Inc.: Irvine, CA, 1998. 307 pp. ISBN 1-890661-06-6. 30.00. This workbook is the latest in a series of "lab manuals" designed to increase the presence of molecular modeling and computational chemistry in undergraduate courses. The authors have designed the workbook to differ from its predecessors in two ways: the target audience is introductory organic chemistry students, and a CD-ROM containing files of molecules and data replaces the need for expensive molecular modeling software. It also differs from its predecessors in that the exercises in it are not really molecular modeling experiments. Instead, students are introduced to the field by viewing the results of computational work stored on the CD-ROM. The workbook is divided into 21 chapters, each of which covers a topic encountered in introductory-level organic chemistry. The sequence of chapters follows the sequence of topics that instructors of introductory organic courses might employ, allowing the workbook to be used with most modern organic chemistry texts. The heart of the workbook, though, is the CD-ROM included with the book. It contains files of molecules and their accompanying computational results as well as Spartan View, a software package that allows these models to be visualized. Although it does not allow actual calculations to be performed, Spartan View permits the user to rotate molecules, intermediates, and transition states and retrieve "precalculated" values of bond and dihedral angles, bond lengths, energies, dipole moments, charge, and frequency of vibration. Spartan View also allows the user to search molecules and intermediates for electron-rich or electron-poor regions by showing electrostatic potential as well as HOMOs and LUMOs. Some files allow for animation of reactions or conformational changes. Note, however, that since the data are just stored on the CD-ROM, not all the data are available for all files. Although performing calculations is not an option, Spartan View can be used to display models and data obtained using Spartan or MacSpartan and stored on a disk. In this way, student exercises can be customized by the instructor or the instructor can prepare customized examples for use in lecture. Each chapter in the workbook contains a series of 3 to 17 exercises that use models and associated data contained on the accompanying CD-ROM. The exercises are not simply cookbook procedures in which the student is directed how to solve a problem. Instead, the authors provide background in a two-part tutorial and several essays that describe the information that can be obtained through molecular modeling, and then introduce a problem in organic chemistry that can be addressed using molecular modeling. The student is left to determine how best to obtain the requested data. For example, an exercise in the chapter Acids & Bases directs the student to determine the atomic charges and view the electrostatic potential map of the conjugate bases of three organic acids. The student is not, however, told which menu to pull or button to push. At the end of the exercise, the student is directed to compare the reactivity of the acids with the data collected from Spartan View. The exercises are relatively easy to complete after spending a few minutes with the tutorials, and many require students to compare the results of calculations with the reactivity of the molecules as discussed in the traditional lecture portion of the course. In this sense, the workbook provides a meaningful link between molecular modeling exercises outside of class and activities in the classroom. While some exercises involve comparing the energies of intermediates or transition states, others are more like videos of processes. Instructors will find many of these to be useful as visual aids in lecture. Mechanisms of Ring Inversion, for example, allows the instructor to show the stepwise ring flip of cyclohexane. Although some of the animations are very similar to those contained on CD-ROMs that sometimes accompany textbooks, the exercises in this

Crouch, R. David

1999-09-01

440

Chemistry Rocks: Redox Chemistry as a Geologic Tool.  

ERIC Educational Resources Information Center

Applies chemistry to earth science, uses rocks in chemistry laboratories, and teaches about transition metal chemistry, oxidation states, and oxidation-reduction reactions from firsthand experiences. (YDS)

Burns, Mary Sue

2001-01-01

441

The Atmospheric Chemistry Experiment (ACE): overview of the ACE Validation Program  

NASA Astrophysics Data System (ADS)

The ACE Validation Program is a program of validation comparison studies designed to continue throughout the life of the mission. The initial phase has been completed recently with the submission of papers for a special issue of Atmospheric Chemistry and Physics - Validation results for the Atmospheric Chemistry Experiment (ACE). These studies provided results for O3 , H2 O, CO, CH4 , HCl, HF, CFC-11, CFC-12, NO, NO2 , N2 O5 , HNO3 , ClONO2 , N2 O, temperature and aerosol extinction. During the on-going validation phase, this comparison work will continue as new data versions are released and additional products are developed. In support of the ACE Validation Program, five measurement campaigns have been held during polar sunrise in Eureka, Nunavut, Canada (80° N, 86° W). Between February and April in 2004 - 2008, a suite of up to 12 ground-based instruments, as well as balloon-borne ozonesondes and radiosondes, have taken part in the Canadian Arctic ACE Validation campaigns at the Polar Environment Atmospheric Research Laboratory (PEARL). This period coincides with the most chemically active time of year in the Arctic, as well as a significant number of satellite overpasses. This presentation will describe the ACE Validation Program and highlight results from the initial phase comparisons. Results obtained during the Canadian Arctic ACE Validation campaigns will also be presented.

Walker, Kaley

442

UCLA PHYSICAL CHEMISTRY CONCENTRATION 2012-2013 CHEMISTRY MAJOR (B.S.), PHYSICAL CHEMISTRY CONCENTRATION: This concentration is designed primarily for  

E-print Network

engineering, physical chemistry, physical inorganic chemistry, biophysical chemistry, or physical organicUCLA PHYSICAL CHEMISTRY CONCENTRATION 2012-2013 CHEMISTRY MAJOR (B.S.), PHYSICAL CHEMISTRY CONCENTRATION: This concentration is designed primarily for Chemistry majors who are interested in attending

Levine, Alex J.

443

Dissolved organic carbon trends resulting from changes in atmospheric deposition chemistry.  

PubMed

Several hypotheses have been proposed to explain recent, widespread increases in concentrations of dissolved organic carbon (DOC) in the surface waters of glaciated landscapes across eastern North America and northern and central Europe. Some invoke anthropogenic forcing through mechanisms related to climate change, nitrogen deposition or changes in land use, and by implication suggest that current concentrations and fluxes are without precedent. All of these hypotheses imply that DOC levels will continue to rise, with unpredictable consequences for the global carbon cycle. Alternatively, it has been proposed that DOC concentrations are returning toward pre-industrial levels as a result of a gradual decline in the sulphate content of atmospheric deposition. Here we show, through the assessment of time series data from 522 remote lakes and streams in North America and northern Europe, that rising trends in DOC between 1990 and 2004 can be concisely explained by a simple model based solely on changes in deposition chemistry and catchment acid-sensitivity. We demonstrate that DOC concentrations have increased in proportion to the rates at which atmospherically deposited anthropogenic sulphur and sea salt have declined. We conclude that acid deposition to these ecosystems has been partially buffered by changes in organic acidity and that the rise in DOC is integral to recovery from acidification. Over recent decades, deposition-driven increases in organic matter solubility may have increased the export of DOC to the oceans, a potentially important component of regional carbon balances. The increase in DOC concentrations in these regions appears unrelated to other climatic factors. PMID:18033294

Monteith, Donald T; Stoddard, John L; Evans, Christopher D; de Wit, Heleen A; Forsius, Martin; Høgåsen, Tore; Wilander, Anders; Skjelkvåle, Brit Lisa; Jeffries, Dean S; Vuorenmaa, Jussi; Keller, Bill; Kopácek, Jiri; Vesely, Josef

2007-11-22

444

Research in physical chemistry and chemical education: Part A: Water Mediated Chemistry of Oxidized Atmospheric Compounds Part B: The Development of Surveying Tools to Determine How Effective Laboratory Experiments Contribute to Student Conceptual Understanding  

NASA Astrophysics Data System (ADS)

This dissertation is a combination of two research areas, experimental physical chemistry, Chapters I to V, and chemical education, Chapters VI to VII. Chapters I to V describe research on the water-mediated chemistry of oxidized atmospheric molecules and the impact that water has on the spectra of these environmental systems. The role of water in the Earth's atmosphere has been of considerable interest due to its ability to impact chemistry and climate. Oxidized atmospheric molecules in the presence of water have the ability to form hydrogen bonded water complexes. The spectroscopic investigation of nitric acid-water complexes, outlined in Chapter III, was undertaken to characterize intermolecular hydrogen bonds in a water-restricted environment at ambient temperatures. Additionally, this characterization of nitric acid-water complexes allowed for the comparison of calculated overtone OH-stretching vibrational band frequencies, intensities, and anharmonicities of intermolecular hydrogen-bonded water complexes with experimental observations. Oxidized organic molecules, such as aldehydes and ketones, in addition to forming hydrogen-bonded water complexes can undergo a hydration reaction of the carbonyl group and form germinal diols in the presence of water. This chemistry has been studied extensively in bulk aqueous media, however little is known about this process in the gas-phase at low water concentrations. The focus of the studies outlined in Chapters IV and V is motivated by the ability of pyruvic acid and formaldehyde to form germinal diols and water complexes in water-restricted environment. This water-mediated chemistry changes the physical and chemical properties of these organic molecules, therefore, impacting the partitioning between gas and particle phase, as well as the chemistry and photochemistry of oxidized organic molecules in the Earth's atmosphere. The results presented in this dissertation may help resolve the significant discrepancy between atmospherically measured oxidized organic molecules and predictions of atmospheric models at different relative humidities. The chemical education portion of this manuscript presented in Chapters VI and VII includes the development of a survey to determine how effective a laboratory experiment is in contributing to students' understanding of fundamental chemistry. The specific example used is an electrochemical cell. Our initial results showed that while most of our students could answer quantitative questions about the operation of the cell, their conceptual understanding of the microscopic processes that occur within the cell was inconsistent with the material presented in class. In particular, we noticed that while many students were able to correctly describe the events that take place at the surface of the anode and cathode, their understanding of the events that take place at the salt bridge was lacking. In this investigation, we were able to confirm the misconceptions reported in previous studies. Our results suggest that a relatively modest, incremental revision of the experiment reduces these misconceptions and helped the students to develop a molecular-scale picture of the processes that occur within an electrochemical cell.

Maron, Marta Katarzyna

445

The impact of recirculation, ventilation and filters on secondary organic aerosols generated by indoor chemistry  

Microsoft Academic Search

This study examined the impact of recirculation rates (7 and 14 h?1), ventilation rates (1 and 2 h?1), and filtration on secondary organic aerosols (SOAs) generated by ozone of outdoor origin reacting with limonene of indoor origin. Experiments were conducted within a recirculating air handling system that serviced an unoccupied, 236 m3 environmental chamber configured to simulate an office; either no filter, a

M. O. Fadeyi; C. J. Weschler; K. W. Tham

2009-01-01

446

Carbon cycling and phytoplankton responses within highly-replicated shipboard carbonate chemistry manipulation experiments conducted around Northwest European Shelf Seas  

NASA Astrophysics Data System (ADS)

The ongoing oceanic uptake of anthropogenic carbon dioxide (CO2) is significantly altering the carbonate chemistry of seawater, a phenomenon referred to as ocean acidification. Experimental manipulations have been increasingly used to gauge how continued ocean acidification will potentially impact marine ecosystems and their associated biogeochemical cycles in the future; however, results amongst studies, particularly when performed on natural communities, are highly variable, which in part likely reflects inconsistencies in experimental approach. To investigate the potential for identification of more generic responses and greater experimentally reproducibility, we devised and implemented a series of highly replicated (n = 8), short term (2-4 days) multi-level (? 4 conditions) carbonate chemistry/nutrient manipulation experiments on a range of natural microbial communities sampled in Northwest European shelf seas. Carbonate chemistry manipulations and resulting biological responses were found to be highly reproducible within individual experiments and to a lesser extent between geographically different experiments. Statistically robust reproducible physiological responses of phytoplankton to increasing pCO2, characterized by a suppression of net growth for small sized cells (< 10 ?m), were observed in the majority of the experiments, irrespective of nutrient status. Remaining between-experiment variability was potentially linked to initial community structure and/or other site-specific environmental factors. Analysis of carbon cycling within the experiments revealed the expected increased sensitivity of carbonate chemistry to biological processes at higher pCO2 and hence lower buffer capacity. The results thus emphasize how biological-chemical feedbacks may be altered in the future ocean.

Richier, S.; Achterberg, E. P.; Dumousseaud, C.; Poulton, A. J.; Suggett, D. J.; Tyrrell, T.; Zubkov, M. V.; Moore, C. M.

2014-03-01

447

Natural organic matter removal by nanofiltration: effects of solution chemistry on retention of low molar mass acids versus bulk organic matter   

E-print Network

The main emphasis of this study is the difference in behaviour between those two organic types. Stirred cell experiments were used to investigate charge and size effects in the rejection behaviour of bulk natural organics ...

Schäfer, Andrea; Pihlajamäki, A.; Fane, Anthony G.; Waite, T. D.; Nyström, M.

2004-01-01

448

First Global Observations of Atmospheric COCIF from the Atmospheric Chemistry Experiment Mission  

NASA Technical Reports Server (NTRS)

Carbonyl chlorofluoride (COCIF) is an important reservoir of chlorine and fluorine in the Earth's atmosphere. Satellite-based remote sensing measurements of COCIF, obtained by the Atmospheric Chemistry Experiment (ACE) for a time period spanning February 2004 through April 2007, have been used in a global distribution study. There is a strong source region for COCIF in the tropical stratosphere near 27 km. A layer of enhanced COCIF spans the low- to mid-stratosphere over all latitudes, with volume mixing ratios of 40-100 parts per trillion by volume, largest in the tropics and decreasing toward the poles. The COCIF volume mixing ratio profiles are nearly zonally symmetric, but they exhibit a small hemispheric asymmetry that likely arises from a hemispheric asymmetry in the parent molecule CCl3 F. Comparisons are made with a set of in situ stratospheric measurements from the mid-1980s and with predictions from a 2-D model.

Fu, Dejian; Boone, Chris D.; Bernath, Peter F.; Weisenstein, Debra K.; Rinsland, Curtis P.; Manney, Gloria L.; Walker, Kaley A.

2010-01-01

449

Measurement of Henry's Law Constants Using Internal Standards: A Quantitative GC Experiment for the Instrumental Analysis or Environmental Chemistry Laboratory  

ERIC Educational Resources Information Center

An internal standard method applicable to undergraduate instrumental analysis or environmental chemistry laboratory has been designed and tested to determine the Henry's law constants for a series of alkyl nitriles. In this method, a mixture of the analytes and an internal standard is prepared and used to make a standard solution (organic solvent)…

Ji, Chang; Boisvert, Susanne M.; Arida, Ann-Marie C.; Day, Shannon E.

2008-01-01

450

Determination of Molecular Self-Diffusion Coefficients Using Pulsed-Field-Gradient NMR: An Experiment for Undergraduate Physical Chemistry Laboratory  

ERIC Educational Resources Information Center

NMR spectroscopy has become one of the primary tools that chemists utilize to characterize a range of chemical species in the solution phase, from small organic molecules to medium-sized proteins. A discussion of NMR spectroscopy is an essential component of physical and biophysical chemistry lecture courses, and a number of instructional…

Harmon, Jennifer; Coffman, Cierra; Villarrial, Spring; Chabolla, Steven; Heisel, Kurt A.; Krishnan, Viswanathan V.

2012-01-01

451

A Conversion of Methyl Ketones into Acetylenes: A Project for a Problem-Oriented or Microscale Organic Chemistry Course.  

ERIC Educational Resources Information Center

Describes a process for producing terminal or internal alkynes from ketones. Recommends using the experiment to aid in understanding acid-base strength, enolate anion chemistry, reaction at carbon versus oxygen, use of polar aprotic solvents, and elimination and nucleophilic substitution reactions. (ML)

Silveira, Augustine, Jr.; Orlando, Steven C.

1988-01-01

452

Secondary organic aerosol production from diesel vehicle exhaust: impact of aftertreatment, fuel chemistry and driving cycle  

NASA Astrophysics Data System (ADS)

Environmental chamber ("smog chamber") experiments were conducted to investigate secondary organic aerosol (SOA) production from dilute emissions from two medium-duty diesel vehicles (MDDVs) and three heavy-duty diesel vehicles (HDDVs) under urban-like conditions. Some of the vehicles were equipped with emission control aftertreatment devices, including diesel particulate filters (DPFs), selective catalytic reduction (SCR) and diesel oxidation catalysts (DOCs). Experiments were also performed with different fuels (100% biodiesel and low-, medium- or high-aromatic ultralow sulfur diesel) and driving cycles (Unified Cycle,~Urban Dynamometer Driving Schedule, and creep + idle). During normal operation, vehicles with a catalyzed DPF emitted very little primary particulate matter (PM). Furthermore, photooxidation of dilute emissions from these vehicles produced essentially no SOA (below detection limit). However, significant primary PM emissions and SOA production were measured during active DPF regeneration experiments. Nevertheless, under reasonable assumptions about DPF regeneration frequency, the contribution of regeneration emissions to the total vehicle emissions is negligible, reducing PM trapping efficiency by less than 2%. Therefore, catalyzed DPFs appear to be very effective in reducing both primary PM emissions and SOA production from diesel vehicles. For both MDDVs and HDDVs without aftertreatment substantial SOA formed in the smog chamber - with the emissions from some vehicles generating twice as much SOA as primary organic aerosol after 3 h of oxidation at typical urban VOC / NOx ratios (3 : 1). Comprehensive organic gas speciation was performed on these emissions, but less than half of the measured SOA could be explained by traditional (speciated) SOA precursors. The remainder presumably originates from the large fraction (~30%) of the nonmethane organic gas emissions that could not be speciated using traditional one-dimensional gas chromatography. The unspeciated organics - likely comprising less volatile species such as intermediate volatility organic compounds - appear to be important SOA precursors; we estimate that the effective SOA yield (defined as the ratio of SOA mass to reacted precursor mass) was 9 ± 6% if both speciated SOA precursors and unspeciated organics are included in the analysis. SOA production from creep + idle operation was 3-4 times larger than SOA production from the same vehicle operated over the Urban Dynamometer Driving Schedule (UDDS). Fuel properties had little or no effect on primary PM emissions or SOA formation.

Gordon, T. D.; Presto, A. A.; Nguyen, N. T.; Robertson, W. H.; Na, K.; Sahay, K. N.; Zhang, M.; Maddox, C.; Rieger, P.; Chattopadhyay, S.; Maldonado, H.; Maricq, M. M.; Robinson, A. L.

2014-05-01

453

Secondary organic aerosol production from diesel vehicle exhaust: impact of aftertreatment, fuel chemistry and driving cycle  

NASA Astrophysics Data System (ADS)

Environmental chamber ("smog chamber") experiments were conducted to investigate secondary organic aerosol (SOA) production from dilute emissions from two medium-duty diesel vehicles (MDDVs) and three heavy-duty diesel vehicles (HDDVs) under urban-like conditions. Some of the vehicles were equipped with emission control aftertreatment devices including diesel particulate filters (DPF), selective catalytic reduction (SCR) and diesel oxidation catalysts (DOC). Experiments were also performed with different fuels (100% biodiesel and low-, medium- or high-aromatic ultralow sulfur diesel) and driving cycles (Unified Cycle, Urban Dynamometer Driving Schedule, and creep+idle). During normal operation, vehicles with a catalyzed DPF emitted very little primary particulate matter (PM). Furthermore, photo-oxidation of dilute emissions from these vehicles produced essentially no SOA (below detection limit). However, significant primary PM emissions and SOA production were measured during active DPF regeneration experiments. Nevertheless, under reasonable assumptions about DPF regeneration frequency, the contribution of regeneration emissions to the total vehicle emissions is negligible, reducing PM trapping efficiency by less than 2%. Therefore, catalyzed DPFs appear to be very effective in reducing both primary and secondary fine particulate matter from diesel vehicles. For both MDDVs and HDDVs without aftertreatment substantial SOA formed in the smog chamber - with the emissions from some vehicles generating twice as much SOA as primary organic aerosol after three hours of oxidation at typical urban VOC : NOx ratios (3:1). Comprehensive organic gas speciation was performed on these emissions, but less than half of the measured SOA could be explained by traditional (speciated) SOA precursors. The remainder presumably originates from the large fraction (~30%) of the non-methane organic gas emissions that could not be speciated using traditional one-dimensional gas-chromatography. The unspeciated organics - likely comprising less volatile species, such as intermediate volatility organic compounds - appear to be important SOA precursors; we estimate that the effective SOA yield (defined as the ratio of SOA mass to reacted precursor mass) was 9 ± 6% if both speciated SOA precursors and unspeciated organics are included in the analysis. SOA production from creep+idle operation was 3-4 times larger than SOA production from the same vehicle operated over the Urban Dynamometer Driving Schedule (UDDS). Fuel properties had little or no effect on primary PM emissions or SOA formation.

Gordon, T. D.; Presto, A. A.; Nguyen, N. T.; Robertson, W. H.; Na, K.; Sahay, K. N.; Zhang, M.; Maddox, C.; Rieger, P.; Chattopadhyay, S.; Maldonado, H.; Maricq, M. M.; Robinson, A. L.

2013-09-01

454

Evaluation of the MOCAGE Chemistry Transport Model during the ICARTT/ITOP Experiment  

NASA Technical Reports Server (NTRS)

We evaluate the Meteo-France global chemistry transport 3D model MOCAGE (MOdele de Chimie Atmospherique a Grande Echelle) using the important set of aircraft measurements collected during the ICARRT/ITOP experiment. This experiment took place between US and Europe during summer 2004 (July 15-August 15). Four aircraft were involved in this experiment providing a wealth of chemical data in a large area including the North East of US and western Europe. The model outputs are compared to the following species of which concentration is measured by the aircraft: OH, H2O2, CO, NO, NO2, PAN, HNO3, isoprene, ethane, HCHO and O3. Moreover, to complete this evaluation at larger scale, we used also satellite data such as SCIAMACHY NO2 and MOPITT CO. Interestingly, the comprehensive dataset allowed us to evaluate separately the model representation of emissions, transport and chemical processes. Using a daily emission source of biomass burning, we obtain a very good agreement for CO while the evaluation of NO2 points out incertainties resulting from inaccurate ratio of emission factors of NOx/CO. Moreover, the chemical behavior of O3 is satisfactory as discussed in the paper.

Bousserez, N.; Attie, J. L.; Peuch, V. H.; Michou, M.; Pfister, G.; Edwards, D.; Emmons, L.; Arnold, S.; Heckel, A.; Richter, A.; Shlager, H.; Lewis A.; Avery, M.; Sachse, G.; Browell, E.; Ferrare, R.

2007-01-01

455

A new Geoengineering Model Intercomparison Project (GeoMIP) experiment designed for climate and chemistry models  

NASA Astrophysics Data System (ADS)

A new Geoengineering Model Intercomparison Project (GeoMIP) experiment "G4 specified stratospheric aerosols" (short name: G4SSA) is proposed to investigate the impact of stratospheric aerosol geoengineering on atmospheric composition, climate, and the environment. In contrast to the earlier G4 GeoMIP experiment, which requires an emission of sulphur dioxide (SO2) into the model, a prescribed aerosol forcing file is provided to the community, to be consistently applied to future model experiments between 2020 and 2100. This stratospheric aerosol distribution, with a total burden of about 2 Tg S has been derived using the ECHAM5-HAM microphysical model, based on a continuous annual tropical emission of 8 Tg SO2 year-1. A ramp-up of geoengineering in 2020 and a ramp-down in 2070 over a period of two years are included in the distribution, while a background aerosol burden should be used for the last 3 decades of the experiment. The performance of this experiment using climate and chemistry models in a multi-model comparison framework will allow us to better understand the significance of the impact of geoengineering and the abrupt termination after 50 years on climate and composition of the atmosphere in a changing environment. The zonal and monthly mean stratospheric aerosol input dataset is available at https://www2.acd.ucar.edu/gcm/geomip-g4-specified-stratospheric-aerosol-data-set.

Tilmes, S.; Mills, M. J.; Niemeier, U.; Schmidt, H.; Robock, A.; Kravitz, B.; Lamarque, J.-F.; Pitari, G.; English, J. M.

2014-08-01

456

Heterogeneous Chemistry of Glyoxal on Acidic Solutions. An Oligomerization Pathway for Secondary Organic Aerosol Formation.  

PubMed

The heterogeneous chemistry of glyoxal on sulfuric acid surfaces has been investigated at various acid concentrations and temperatures, utilizing a low-pressure fast flow laminar reactor coupled to an ion drift-chemical ionization mass spectrometer (ID-CIMS). The uptake coefficient (?) of glyoxal ranges from (1.2 ± 0.06) × 10(-2) to (2.5 ± 0.01) × 10(-3) for 60-93 wt % H2SO4 at 253-273 K. The effective Henry's Law constant (H*) ranges from (98.9 ± 4.9) × 10(5) to (1.6 ± 0.1) × 10(5) M atm(-1) for 60-93 wt % at 263-273 K. Both the uptake coefficient and Henry's Law constant increase with decreasing acid concentration and temperature. Our results reveal a reaction mechanism of hydration followed by oligomerization for glyoxal on acidic media, indicating an efficient aqueous reaction of glyoxal on hygroscopic particles leading to secondary organic aerosol formation. PMID:25369518

Gomez, Mario E; Lin, Yun; Guo, Song; Zhang, Renyi

2014-11-20

457

Meaningful Understanding and Systems Thinking in Organic Chemistry: Validating Measurement and Exploring Relationships  

NASA Astrophysics Data System (ADS)

The purpose of this study was dual: First, to develop and validate assessment schemes for assessing 11th grade students' meaningful understanding of organic chemistry concepts, as well as their systems thinking skills in the domain. Second, to explore the relationship between the two constructs of interest based on students' performance on the applied assessment framework. For this purpose, (a) various types of objective assessment questions were developed and evaluated for assessing meaningful understanding, (b) a specific type of systemic assessment questions (SAQs) was developed and evaluated for assessing systems thinking skills, and (c) the association between students' responses on the applied assessment schemes was explored. The results indicated that properly designed objective questions can effectively capture aspects of students' meaningful understanding. It was also found that the SAQs can elicit systems thinking skills in the context of a formalistic systems thinking theoretical approach. Moreover, a significant relationship was observed between students' responses on the two assessment strategies. This research provides evidence that students' systems thinking level within a science domain is significantly related to their meaningful understanding of relative science concepts.

Vachliotis, Theodoros; Salta, Katerina; Tzougraki, Chryssa

2014-04-01

458

Nucleic acid chemistry in the organic phase: from functionalized oligonucleotides to DNA side chain polymers.  

PubMed

DNA-incorporating hydrophobic moieties can be synthesized by either solid-phase or solution-phase coupling. On a solid support the DNA is protected, and hydrophobic units are usually attached employing phosphoramidite chemistry involving a DNA synthesizer. On the other hand, solution coupling in aqueous medium results in low yields due to the solvent incompatibility of DNA and hydrophobic compounds. Hence, the development of a general coupling method for producing amphiphilic DNA conjugates with high yield in solution remains a major challenge. Here, we report an organic-phase coupling strategy for nucleic acid modification and polymerization by introducing a hydrophobic DNA-surfactant complex as a reactive scaffold. A remarkable range of amphiphile-DNA structures (DNA-pyrene, DNA-triphenylphosphine, DNA-hydrocarbon, and DNA block copolymers) and a series of new brush-type DNA side-chain homopolymers with high DNA grafting density are produced efficiently. We believe that this method is an important breakthrough in developing a generalized approach to synthesizing functional DNA molecules for self-assembly and related technological applications. PMID:25265497

Liu, Kai; Zheng, Lifei; Liu, Qing; de Vries, Jan Willem; Gerasimov, Jennifer Y; Herrmann, Andreas

2014-10-01

459

Creating a Discovery Platform for Confined-Space Chemistry and Materials: Metal-Organic Frameworks.  

SciTech Connect

Metal organic frameworks (MOF) are a recently discovered class of nanoporous, defect-free crystalline materials that enable rational design and exploration of porous materials at the molecular level. MOFs have tunable monolithic pore sizes and cavity environments due to their crystalline nature, yielding properties exceeding those of most other porous materials. These include: the lowest known density (91% free space); highest surface area; tunable photoluminescence; selective molecular adsorption; and methane sorption rivaling gas cylinders. These properties are achieved by coupling inorganic metal complexes such as ZnO4 with tunable organic ligands that serve as struts, allowing facile manipulation of pore size and surface area through reactant selection. MOFs thus provide a discovery platform for generating both new understanding of chemistry in confined spaces and novel sensors and devices based on their unique properties. At the outset of this project in FY06, virtually nothing was known about how to couple MOFs to substrates and the science of MOF properties and how to tune them was in its infancy. An integrated approach was needed to establish the required knowledge base for nanoscale design and develop methodologies integrate MOFs with other materials. This report summarizes the key accomplishments of this project, which include creation of a new class of radiation detection materials based on MOFs, luminescent MOFs for chemical detection, use of MOFs as templates to create nanoparticles of hydrogen storage materials, MOF coatings for stress-based chemical detection using microcantilevers, and %22flexible%22 force fields that account for structural changes in MOFs that occur upon molecular adsorption/desorption. Eight journal articles, twenty presentations at scientific conferences, and two patent applications resulted from the work. The project created a basis for continuing development of MOFs for many Sandia applications and succeeded in securing %242.75 M in funding from outside agencies to continue the research. 3

Allendorf, Mark D.; Greathouse, Jeffery A. [Sandia National Laboratories, Albuquerque, NM; Simmons, Blake

2008-09-01

460

Estimating the One-Electron Reduction Potential for Vanadium (V) by Chemical Techniques: An Experiment for General Chemistry.  

ERIC Educational Resources Information Center

Describes an experiment which requires only qualitative observations, is suitable for general chemistry students, prompts an understanding of thermodynamic spontaneity, gives chemical meaning to electrode potentials, requires non-electrochemical equipment, and allows estimates of the standard potential for the reduction of Vanadium (V) to V (IV).…

Wentworth, R. A. D.

1985-01-01

461

Preparation and Reactions of the 1,1-Dithiolato Complexes of Ni(II). An Undergraduate Coordination Chemistry Experiment.  

ERIC Educational Resources Information Center

Described is an undergraduate coordination chemistry experiment that enables students to relate concepts developed in class about the stereochemistry and coordination numbers to the interpretation of the electronic and infrared spectra and their magnetic behavior. Indicates that thermal decomposition and x-ray diffraction studies can also be…

Ballester, L.; Perpinan, M. F.

1988-01-01

462

The Quantitative Resolution of a Mixture of Group II Metal Ions by Thermometric Titration with EDTA. An Analytical Chemistry Experiment.  

ERIC Educational Resources Information Center

Presents an experiment in thermometric titration used in an analytic chemistry-chemical instrumentation course, consisting of two titrations, one a mixture of calcium and magnesium, the other of calcium, magnesium, and barium ions. Provides equipment and solutions list/specifications, graphs, and discussion of results. (JM)

Smith, Robert L.; Popham, Ronald E.

1983-01-01

463

An Advanced Analytical Chemistry Experiment Using Gas Chromatography-Mass Spectrometry, MATLAB, and Chemometrics to Predict Biodiesel Blend Percent Composition  

ERIC Educational Resources Information Center

We present a laboratory experiment for an advanced analytical chemistry course where we first focus on the chemometric technique partial least-squares (PLS) analysis applied to one-dimensional (1D) total-ion-current gas chromatography-mass spectrometry (GC-TIC) separations of biodiesel blends. Then, we focus on n-way PLS (n-PLS) applied to…

Pierce, Karisa M.; Schale, Stephen P.; Le, Trang M.; Larson, Joel C.

2011-01-01

464

[60]Fullerene Displacement from (Dihapto-Buckminster-Fullerene) Pentacarbonyl Tungsten(0): An Experiment for the Inorganic Chemistry Laboratory, Part II  

ERIC Educational Resources Information Center

The kinetics experiments on the ligand-C[subscript 60] exchange reactions on (dihapto-[60]fullerene) pentacarbonyl tungsten(0), ([eta][superscript 2]-C[subscript 60])W(CO)[subscript 5], form an educational activity for the inorganic chemistry laboratory that promotes graphical thinking as well as the understanding of kinetics, mechanisms, and the…

Cortes-Figueroa, Jose E.; Moore-Russo, Deborah A.

2006-01-01

465

Sol-Gel Synthesis of a Biotemplated Inorganic Photocatalyst: A Simple Experiment for Introducing Undergraduate Students to Materials Chemistry  

ERIC Educational Resources Information Center

As part of a laboratory course, undergraduate students were asked to use baker's yeast cells as biotemplate in preparing TiO[subscript 2] powders and to test the photocatalytic activity of the resulting materials. This laboratory experience, selected because of the important environmental implications of soft chemistry and photocatalysis, provides…

Boffa, Vittorio; Yue, Yuanzheng; He, Wen

2012-01-01

466

Removal of Aromatic Pollutant Surrogate from Water by Recyclable Magnetite-Activated Carbon Nanocomposite: An Experiment for General Chemistry  

ERIC Educational Resources Information Center

A general chemistry laboratory experiment using readily available chemicals is described to introduce college students to an exciting class of nanocomposite materials. In a one-step room temperature synthetic process, magnetite nanoparticles are embedded onto activated carbon matrix. The resultant nanocomposite has been shown to combine the…

Furlan, Ping Y.; Melcer, Michael E.

2014-01-01

467

Observation and Analysis of N[subscript 2]O Rotation-Vibration Spectra: A Physical Chemistry Laboratory Experiment  

ERIC Educational Resources Information Center

The linear molecule N[subscript 2]O is presented as an alternative gas-phase species for the ubiquitous undergraduate physical chemistry rotation-vibration spectroscopy experiment. Utilizing a 0.5 cm[superscript -1] resolution teaching grade FTIR spectrometer, 15 vibrational bands, corresponding to 1229 rotation-vibration transitions, have been…

Bryant, Mark S.; Reeve, Scott W.; Burns, William A.

2008-01-01

468

A Simple Experiment in the Separation of a Solid-Phase Mixture and Infrared Spectroscopy for Introductory Chemistry  

ERIC Educational Resources Information Center

This experiment was developed as a means of incorporating instrumental analyses into an introductory chemistry laboratory. A two-component solid mixture of caffeine and ibuprofen is separated through a series of solution extractions and precipitation and their relative amounts measured. These compounds were chosen because the combination of…

Szalay, Paul S.

2008-01-01

469

Ionic Strength Effect on the Rate of Reduction of Hexacyanoferrate (III) by Ascorbic Acid: A Physical Chemistry Laboratory Experiment.  

ERIC Educational Resources Information Center

Describes a physical chemistry experiment that allows students to test the effect of ionic strength on the rates of a reaction between ions. The reduction of hexacyanoferrate III by ascorbic acid is detailed. Comparisons with the iodine clock reaction are made. (CS)

Watkins, Kenneth W.; Olson, June A.

1980-01-01

470

Utilization of a Microcomputer for the Study of an Iodine Oxidation and Equilibrium Reaction: A Physical Chemistry Experiment.  

ERIC Educational Resources Information Center

Describes a physical chemistry experiment which incorporates the use of a microcomputer to enhance understanding of combined kinetic and equilibrium phenomena, to increase experimental capabilities when working with large numbers of students and limited equipment, and for the student to develop a better understanding of experimental design. (JN)

Julien, L. M.

1984-01-01

471

Temperature and Electron Density Determination on Laser-Induced Breakdown Spectroscopy (LIBS) Plasmas: A Physical Chemistry Experiment  

ERIC Educational Resources Information Center

This laboratory is designed for physical chemistry students to gain experience using laser-induced breakdown spectroscopy (LIBS) in understanding plasma diagnostics. LIBS uses a high-powered laser that is focused on the sample causing a plasma to form. The emission of this plasma is then spectrally resolved and detected. Temperature and electron…

Najarian, Maya L.; Chinni, Rosemarie C.

2013-01-01

472

Binary Solid-Liquid Phase Diagram of Phenol and t-Butanol: An Undergraduate Physical Chemistry Experiment  

ERIC Educational Resources Information Center

The determination of the solid-liquid phase diagram of a binary system is always used as an experiment in the undergraduate physical chemistry laboratory courses. However, most phase diagrams investigated in the lab are simple eutectic ones, despite the fact that complex binary solid-liquid phase diagrams are more common. In this article, the…

Xu, Xinhua; Wang, Xiaogang; Wu, Meifen

2014-01-01

473

TextRev: A Window into How General and Organic Chemistry Students Use Textbook Resources.  

ERIC Educational Resources Information Center

Points out the important use of textbooks and their ancillary resources in lower-division chemistry courses and the scientific misconceptions found in them. Introduces the TextRev Project which is a new resource for data collection and analysis. Investigates how first and second year chemistry students use and value their textbooks and their study…

Smith, Bradley D.; Jacobs, Dennis C.

2003-01-01

474

Microwave-assisted chemistry: synthetic applications for rapid assembly of nanomaterials and organics.  

PubMed

The magic of microwave (MW) heating technique, termed the Bunsen burner of the 21st century, has emerged as a valuable alternative in the synthesis of organic compounds, polymers, inorganic materials, and nanomaterials. Important innovations in MW-assisted chemistry now enable chemists to prepare catalytic materials or nanomaterials and desired organic molecules, selectively, in almost quantitative yields and with greater precision than using conventional heating. By controlling the specific MW parameters (temperature, pressure, and ramping of temperature) and choice of solvents, researchers can now move into the next generation of advanced nanomaterial design and development. Microwave-assisted chemical reactions are now well-established practices in the laboratory setting although some controversy lingers as to how MW irradiation is able to enhance or influence the outcome of chemical reactions. Much of the discussion has focused on whether the observed effects can, in all instances, be rationalized by purely thermal Arrhenius-based phenomena (thermal microwave effects), that is, the importance of the rapid heating and high bulk reaction temperatures that are achievable using MW dielectric heating in sealed reaction vessels, or whether these observations can be explained by so-called "nonthermal" or "specific microwave" effects. In recent years, innovative and significant advances have occurred in MW hardware development to help delineate MW effects, especially the use of silicon carbide (SiC) reaction vessels and the accurate measurement of temperature using fiber optic (FO) temperature probes. SiC reactors appear to be good alternatives to MW transparent borosilicate glass, because of their high microwave absorptivity, and as such they serve as valuable tools to demystify the claimed magical MW effects. This enables one to evaluate the influence of the electromagnetic field on the specific chemical reactions, under truly identical conventional heating conditions, wherein temperature is measured accurately by fiber optic (FO) probe. This Account describes the current status of MW-assisted synthesis highlighting the introduction of various prototypes of equipment, classes of organic reactions pursued using nanomaterials, and the synthesis of unique and multifunctional nanomaterials; the ensuing nanomaterials possess zero-dimensional to three-dimensional shapes, such as spherical, hexagonal, nanoprisms, star shapes, and nanorods. The synthesis of well-defined nanomaterials and nanocatalysts is an integral part of nanotechnology and catalysis science, because it is imperative to control their size, shape, and compositional engineering for unique deployment in the field of nanocatalysis and organic synthesis. MW-assisted methods have been employed for the convenient and reproducible synthesis of well-defined noble and transition core-shell metallic nanoparticles with tunable shell thicknesses. Some of the distinctive attributes of MW-selective heating in the synthesis and applications of magnetic nanocatalysts in organic synthesis under benign reaction conditions are highlighted. Sustainable nanomaterials and their applications in benign media are an ideal blend for the development of greener methodologies in organic synthesis; MW heating provides superb value to the overall sustainable process development via process intensification including the flow systems. PMID:24666323

Gawande, Manoj B; Shelke, Sharad N; Zboril, Radek; Varma, Rajender S

2014-04-15

475

The Binding Constant for Complexation of Bilirubin to Bovine Serum Albumin. An Experiment for the Biophysical Chemistry Laboratory  

NASA Astrophysics Data System (ADS)

Students use fluorescence spectroscopy to measure the binding constant for bilirubin-bovine serum albumin complexation by the Method of Continuous Variations. The experiment applies fundamental concepts of physical chemistry to a commercially available system of biological interest. The experiment is easily completed in a single laboratory period, and students obtain binding constants on the order of 10 7, in good agreement with literature values.

Williams, Kathryn R.; Adhyaru, Bhavin; Pierce, Russell E.; Schulman, Stephen G.

2002-01-01

476

A Green Starting Material for Electrophilic Aromatic Substitution for the Undergraduate Organic Laboratory  

ERIC Educational Resources Information Center

Electrophilic aromatic substitution (EAS) experiment is designed for the second-semester and undergraduate organic chemistry laboratory. In the EAS experiment, the principles of green chemistry are discussed and illustrated in conjunction with the presentation of electrophilic aromatic substitution.

Jones-Wilson, T. Michelle; Burtch, Elizabeth A.

2005-01-01

477

Mercury Redox Chemistry in the Negro River Basin, Amazon: The Role of Organic Matter and Solar Light  

Microsoft Academic Search

Pristine water bodies in the Negro River basin, Brazilian Amazon, show relatively high concentrations of mercury. These waters\\u000a are characterized by acidic pH, low concentrations of suspended solids, and high amounts of dissolved organic matter and are\\u000a exposed to intense solar radiation throughout the year. This unique environment creates a very dynamic redox chemistry affecting\\u000a the mobility of mercury due

Wilson F. JardimMarcia; Márcia Cristina Bisinoti; Pedro Sérgio Fadini; Gilmar Silvério da Silva

2010-01-01

478

Laboratory experiments for Titan's ionosphere : the chemistry of N2+, N+, and N2++ nitrogen ions  

NASA Astrophysics Data System (ADS)

Laboratory experiments for Titan's ionosphere : the chemistry of N+ , N+ , and N2+ nitrogen ions 2 2 R. Thissen (1), C. Alcaraz (1), O. Dutuit (1), C. Nicolas (2), H. Soldi-Lose (3), J. Zabka (4), P. Franceschi (5) (1) LCP, Bât. 350, Centre Universitaire Paris-Sud, F-91405 Orsay Cedex, France, (2) Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin BP 48, 91192 Gif-sur-Yvette, France, (3) Institut für Chemie, Fachgruppe Organische Chemie, Technische Universität Berlin, Straße des 17. Juni 135, D-10623 Berlin, (4) J. Heyrovsky Institute of Physical Chemistry, Dolejskova 3, CZ 18223 Praha 8 - Kobylisy, Czech Republik, (5) Dept. of Physics, University of Trento, Via Sommarive 14, 38050 Povo (TN), Italy (christian.alcaraz@lcp.u-psud.fr) N2 is the major neutral componant of Titan's atmosphere, its ionisation by solar radiation and by magnetospheric electron impact is the most important production of ions in Titan's ionosphere. These primary processes not only lead to N+ molecular 2 monocations but also to N+ atomic ions and to N2+ molecular dications, which can 2 pertain some internal or translational excitation. This contribution will summarize our efforts to caracterize in gaz phase laboratory experiments the reactivity of the nitrogen ions with the most important neutral targets of the Titan's atmosphere [1-3]: • N+ + CH4 , C2 H2 , and C2 H6 2 • N+ (3 P, 1 D) + CH4 , and C2 H4 • N2+ + N2 , CH4 , and C2 H4 2 In this work, particular attention has been paid on the effect of internal and/or translational excitation of the primary nitrogen ions on the rate constant and branching ratio of these ion-molecule reactions. The results from these studies have been compared to the literature values when available and some significant differences have been found. These new values have been used as input data in 1D models of the Titan's ionosphere to show the effect on the final density profiles of the main ions [4] and to demonstrate the existence of a N2+2 dication layer [3]. (1) Nicolas, C.; Torrents, R.; Gerlich, D. J. Chem. Phys. 2003, 118, 2723. (2) Alcaraz, C.; Nicolas, C.; Thissen, R.; Zabka, J.; Dutuit, O. J. Phys. Chem. 2004, 108, 9998. 1 (3) Lilensten, J.; Witasse, O.; Simon, C.; Soldi-Lose, H.; Dutuit, O.; Thissen, R.; Alcaraz, C. Geophys. Res. Lett. 2005, 32, L03203. (4) Carrasco, N.; Dutuit, O.; Thissen, R.; Pernot, P.; Banaszkiewicz, M. Planet. Space Sci. accepted. 2

Thissen, R.; Alcaraz, C.; Dutuit, O.; Nicolas, C.; Soldi-Lose, H.; Zabka, J.; Franceschi, P.

479

An overview of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx)  

NASA Astrophysics Data System (ADS)

The Chemistry-Aerosol Mediterranean Experiment (ChArMEx, http://charmex.lsce.ipsl.fr) is a French initiative of the MISTRALS meta-programme (Mediterranean Integrated Studies at Regional And Locals Scales, http://www.mistrals-home.org). It federates a great number of national and international cooperative research actions aiming at a scientific assessment of the present and future state of the atmospheric environment in the Mediterranean Basin, and of its impacts on the regional climate, air quality, and marine biogeochemistry. The target is short-lived particulate and gaseous tropospheric trace species which are the cause of poor air quality events, have two-way interactions with climate, or impact the marine biogeochemistry, in a context of strong regional anthropogenic and climatic pressures. The six ChArMEx work packages include Emissions, Chemical processes and ageing, Transport processes and air quality, Aerosol-radiation-climate interactions, Deposition, and Present and future variability and trends. For several years, efforts have been deployed in several countries to develop (i) a network of relevant stations for atmospheric chemistry at background sites on islands and continental coasts around the basin and (ii) several intensive field campaigns including the operation of surface supersites and various instrumented mobile platforms (large and ultra-light aircraft, sounding and drifting balloons, ZeroCO2 sailboat). This presentation is an attempt to provide an overview of the various experimental, remote sensing and modelling efforts produced and to highlight major findings, by referencing more detailed ChArMEx presentations given in this conference and recently published or submitted papers. During the first phase of the project experimental efforts have been mainly concentrated on the western basin. Plans for the 2nd phase of ChArMEx, more dedicated towards the eastern basin, will also be given. In particular we plan to develop monitoring activities at Cyprus and put more emphasis (i) on aerosol-cloud interactions in cooperation with the FP7/Environment project BACCHUS, (ii) the budget and transport of anthropogenic emissions from megacities, and (iii) processes at the air-sea interface with a proposal for a 1-month oceanographic cruise during a period of dust deposition events, joint with the biogeochemistry component of MISTRALS (project MERMEX: the Marine Ecosystem Response Mediterranean Experiment). Acknowledgements: ChArMEx activities involve about 50 institutes. FD expresses his gratitude to every contributing scientist. ChArMEx is supported by too many agencies for listing them all here. The main overall effort is from France, with ADEME, ANR, CNES, CNRS-INSU, the Collectivité Territoriale de Corse (incl. EU-FEDER funds), Météo-France, CEA and Ecole des Mines de Douai as the main funding agencies.

Dulac, François

2014-05-01

480

The effects of organic matter-mineral interactions and organic matter chemistry on diuron sorption across a diverse range of soils.  

PubMed

Sorption of non-ionic organic compounds to soil is usually expressed as the carbon-normalized partition coefficient (KOC), because it is assumed that the main factor that influences the amount sorbed is the organic carbon content of the soil. However, KOC can vary by a factor of at least ten across a range of soils. We investigated two potential causes of variation in diuron KOC - organic matter-mineral interactions and organic matter chemistry - for a diverse set of 34 soils from Sri Lanka, representing a wide range of soil types. Treatment with hydrofluoric acid (HF-treatment) was used to concentrate soil organic matter. HF-treatment increased KOC for the majority of soils (average factor 2.4). We attribute this increase to the blocking of organic matter sorption sites in the whole soils by minerals. There was no significant correlation between KOC for the whole soils and KOC for the HF-treated soils, indicating that the importance of organic matter-mineral interactions varied greatly amongst these soils. There was as much variation in KOC across the HF-treated soils as there was across the whole soils, indicating that the nature of soil organic matter is also an important contributor to KOC variability. Organic matter chemistry, determined by solid-state (13)C nuclear magnetic resonance (NMR) spectroscopy, was correlated with KOC for the HF-treated soils. In particular, KOC increased with the aromatic C content (R=0.64, p=1×10(-6)), and decreased with O-alkyl C (R=-0.32, p=0.03) and alkyl C (R=-0.41, p=0.004) content. PMID:24972176

Smernik, Ronald J; Kookana, Rai S

2015-01-01