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Novak, Igor – Journal of Chemical Education, 2005
A simple approach that "demystifies" Le Chatelier's principle (LCP) and simulates students to think about fundamental physical background behind the well-known principles is presented. The approach uses microscopic descriptors of matter like energy levels and populations and does not require any assumption about the fixed amount of substance being…
Descriptors: Chemistry, Scientific Principles, Science Education, Energy
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Mills, Nancy S.; Spence, John D.; Bushey, Michelle M. – Journal of Chemical Education, 2005
A series of substituted benzoic acids (SBAs) are prepared by students. The pKa shift, a result of the electron-withdrawing or electron-donating characteristics of the subsistent is examined in reference to the electrophoretic migration behavior of benzoic acid.
Descriptors: Chemistry, Science Education, Science Experiments, Stoichiometry
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Wallace, Justin R.; Lieberman, Deborah L.; Hancock, Matthew T.; Pinhas, Allan R. – Journal of Chemical Education, 2005
A convenient, inexpensive, environment friendly, and regioselective conversion of an aziridine to an oxazolidinone is developed by using iodide salt and CO[2] in water. A description is provided, on the way in which this series of experiments will show students how to change experimental conditions to obtain mainly one desired regiosomer of a…
Descriptors: Chemistry, Science Experiments, Biochemistry, Science Education
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Baar, Marsha R.; Cerrone-Szakal, Andrea L. – Journal of Chemical Education, 2005
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.
Descriptors: Laboratory Experiments, Organic Chemistry, Science Education, Science Experiments
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Schmitz, Guy – Journal of Chemical Education, 2005
The definition of reaction rate is derived and demonstrations are made for the care to be taken while using the term. Reaction rate can be in terms of a reaction property, the extent of reaction and thus it is possible to give a definition applicable in open and closed systems.
Descriptors: Chemistry, Science Education, Science Experiments, Stoichiometry
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Milholland, Rebecca B. R.; Hines, Stefani D. – American Biology Teacher, 2004
A modified version "Tobacco Induced Mutations" of Ames assay experiment provides a meaningful context for students to learn about the concept of mutations by using a known carcinogen that is tobacco. This experiment shows toxicological concept of the dose/response relationship and visually demonstrates when a mutation have occurred in bacteria…
Descriptors: Smoking, Science Education, Science Experiments, Students
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Beckers, Jozef L. – Journal of Chemical Education, 2004
The presence of caffeine in coffee is determined by the use of separation devices and UV-vis spectrophotometry. The results indicate that the use of various analytical tools helps to perceive the higher concentration values obtained through UV-vis spectrophotometry than with separation methods.
Descriptors: Chemistry, Educational Technology, Spectroscopy, Science Experiments
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Kalbus, Gene E.; Lieu, Van T.; Kalbus, Lee H. – Journal of Chemical Education, 2004
The spectrophotometric method assists in the study of potassium permanganate-oxalate reaction. Basic analytical techniques and rules are implemented in the experiment, which can also include the examination of other compounds oxidized by permanganate.
Descriptors: Laboratory Experiments, Chemistry, Spectroscopy, Science Experiments
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DeMeo, Stephen – Journal of Chemical Education, 2004
The existence of different stoichiometries in two basic zinc carbonates helps to explain their decomposition potential, and to select between the two compound formulas, which better describes zinc carbonate. The accuracy of the experiment makes it a viable means for students to perform various quantitative measurements.
Descriptors: Chemistry, Stoichiometry, Science Experiments, Science Education
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Young, Jay A. – Journal of Chemical Education, 2004
A chemical laboratory information profile (CLIP) of the chemical chlorine, produced in small quantities in the laboratory, is presented. The profile summarizes physical and harmful properties, exposure limits, reactivity risks, and symptoms of major exposure for the benefit of teachers and students using the chemical in the laboratory.
Descriptors: Chemistry, Laboratory Experiments, Science Instruction, Science Experiments
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Jacobsen, Erica K. – Journal of Chemical Education, 2004
A water filtration column is devised by students using a two-liter plastic bottle containing gravel, sand, and activated charcoal, to test the filtration potential of the column. Results indicate that the filtration column eliminates many of the contaminating materials, but does not kill bacteria.
Descriptors: Water, Water Quality, Science Experiments, Chemistry
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Poce-Fatou, J. A.; Gil, M. L. A.; Alcantara, R.; Botella, C.; Martin, J. – Journal of Chemical Education, 2004
The interaction between light and matter is examined with the help of a photochemical experiment. This experiment is useful for the investigation of heterogeneous catalysis, semiconductor properties and adsorption phenomena.
Descriptors: Chemistry, Kinetics, Scientific Concepts, Light
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Almy, John – Journal of Chemical Education, 2004
An experiment that relies entirely on NMR signal counting and polarimetric properties to identify an unknown aldohexose, aldopentose, or ketohexose, is developed. The experiment is adaptable to instructional approaches that allow students to develop identification strategies on their own.
Descriptors: Teaching Methods, Science Experiments, Science Instruction, Chemistry
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De Persis, Stephanie; Dollet, Alain; Teyssandier, Francis – Journal of Chemical Education, 2004
It is presented that only simple concepts, mainly taken from activated-complex or transition-state theory, are required to explain and analytically describe the influence of pressure on gas-phase reaction kinetics. The simplest kind of elementary gas-phase reaction is a unimolecular decomposition reaction.
Descriptors: Science Experiments, Kinetics, Chemistry, Science Instruction
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Andrews, Steven S. – Journal of Chemical Education, 2004
The mathematics behind the average absorption cross-section is exactly one third of the maximum value described. The goal is to calculate experimental observables, or other properties of bulk sample, in terms of microscopic molecular parameters.
Descriptors: Mathematics, Molecular Structure, Chemistry, Science Instruction
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