TIGER

Journal Articles: 113 results
Does the Addition of Inert Gases at Constant Volume and Temperature Affect Chemical Equilibrium?  João C. M. Paiva, Jorge Gonçalves, and Susana Fonseca
This article examines three approaches, leading to different conclusions, for answering the question "Does the addition of inert gases at constant volume and temperature modify the state of equilibrium?"
Paiva, João C. M.; Gonçalves, Jorge; Fonseca, Susana. J. Chem. Educ. 2008, 85, 1133.
Equilibrium |
Gases |
Thermodynamics
An Updated Equilibrium Machine  Emeric Schultz
Describes a device that can demonstrate equilibrium and the Le Châtelier principle, as well as kinetic and thermodynamic concepts. The device consists of a leaf blower attached to a plastic container divided into two chambers by a barrier of variable size and form. Styrofoam balls can be exchanged across the barrier when various air pressures are applied by the blower.
Schultz, Emeric. J. Chem. Educ. 2008, 85, 1131.
Equilibrium |
Kinetics |
Thermodynamics
Comment on "Effect of a Perturbation on the Chemical Equilibrium: Comparison with Le Châtelier's Principle"  Mark J. Uline and David S. Corti
In a recent article, Torres presents a thermodynamic analysis of the response of a system initially at chemical equilibrium to an infinitesimal perturbation. While the analysis is correct in this context, Torres argues incorrectly that the general rule so obtained is also valid for finite perturbations.
Uline, Mark J.; Corti, David S. J. Chem. Educ. 2008, 85, 1052.
Equilibrium
Phenolphthalein—Pink Tornado Demonstration  Bruce R. Prall
This demonstration uses the vortex generated by a spinning magnetic stir bar to demonstrate Le Châtelier's principle as it applies to the phenolphthalein equilibrium in water and provides an excellent opportunity to discuss limiting and excess reagents.
Prall, Bruce R. J. Chem. Educ. 2008, 85, 527.
Acids / Bases |
Equilibrium |
Kinetics |
pH
A Simplified Model To Predict the Effect of Increasing Atmospheric CO2 on Carbonate Chemistry in the Ocean  Brian J. Bozlee, Maria Janebo, and Ginger Jahn
The chemistry of dissolved inorganic carbon in seawater is reviewed and used to predict the potential effect of rising levels of carbon dioxide in the atmosphere. It is found that calcium carbonate may become unsaturated in cold surface seawater by the year 2100, resulting in the destruction of calcifying organisms such as coral.
Bozlee, Brian J.; Janebo, Maria; Jahn, Ginger. J. Chem. Educ. 2008, 85, 213.
Applications of Chemistry |
Aqueous Solution Chemistry |
Atmospheric Chemistry |
Equilibrium |
Green Chemistry |
Water / Water Chemistry
An Experimental Approach to Teaching and Learning Elementary Statistical Mechanics  Frank B. Ellis and David C. Ellis
This article details demonstrations that show how equilibrium changes with temperature, energy, and entropy and involve exothermic and endothermic reactions, the dynamic nature of equilibrium, and Le Châtelier's principle.
Ellis, Frank B.; Ellis, David C. J. Chem. Educ. 2008, 85, 78.
Equilibrium |
Kinetics |
Statistical Mechanics |
Thermodynamics
Using the Science Writing Heuristic To Improve Students' Understanding of General Equilibrium  James A. Rudd, II, Thomas J. Greenbowe, and Brian M. Hand
This study examines the performance of students using the Science Writing Heuristic approach, which facilitates scientific inquiry by structuring the laboratory notebook in a format that guides students to answer directed questions, on lecture exams and a laboratory practical exam on chemical equilibrium.
Rudd, James A., II; Greenbowe, Thomas J.; Hand, Brian M. J. Chem. Educ. 2007, 84, 2007.
Equilibrium |
Learning Theories |
TA Training / Orientation |
Student-Centered Learning
Synthesis of Triarylmethane and Xanthene Dyes Using Electrophilic Aromatic Substitution Reactions  James V. McCullagh and Kelly A. Daggett
In this experiment, electrophilic aromatic substitution reactions are used to synthesize several triarylmethane and xanthene dyes (fluorescein, erythrosin B, thymolphthalein, and rhodamine B) using common equipment while avoiding often troublesome, hydroscopic Lewis acids. Subsequent UVvis analysis produce spectra that match commercially available dye samples.
McCullagh, James V.; Daggett, Kelly A. J. Chem. Educ. 2007, 84, 1799.
Acids / Bases |
Aromatic Compounds |
Dyes / Pigments |
Electrophilic Substitution |
Equilibrium |
Synthesis |
UV-Vis Spectroscopy
Equilibrium: A Teaching/Learning Activity  Douglas A. Vander Griend
Suggests a modification to an earlier published classroom activity for the study of chemical equilibrium.
Vander Griend, Douglas A. J. Chem. Educ. 2007, 84, 1428.
Equilibrium
Exception to the Le Châtelier Principle  David S. Corti and Mark J. Uline
Disagreement regarding an apparent exception to the Le Chtelier principle involving the effects of nonideality on the direction in which the ammonia synthesis reaction shifts upon addition of infinitesimal and finite quantities of nitrogen at constant pressure and temperature.
Corti, David S.; Uline, Mark J. J. Chem. Educ. 2007, 84, 1427.
Equilibrium
Exception to the Le Châtelier Principle  Thomas R. Herrinton
Disagreement regarding an apparent exception to the Le Chtelier principle involving the effects of nonideality on the direction in which the ammonia synthesis reaction shifts upon addition of infinitesimal and finite quantities of nitrogen at constant pressure and temperature.
Herrinton, Thomas R. J. Chem. Educ. 2007, 84, 1427.
Equilibrium |
Gases
Exception to the Le Châtelier Principle  Thomas R. Herrinton
Disagreement regarding an apparent exception to the Le Chatelier principle involving the effects of nonideality on the direction in which the ammonia synthesis reaction shifts upon addition of infinitesimal and finite quantities of nitrogen at constant pressure and temperature.
Herrinton, Thomas R. J. Chem. Educ. 2007, 84, 1427.
Equilibrium |
Gases
Effect of a Perturbation on the Chemical Equilibrium: Comparison with Le Châtelier's Principle  Emilio Martínez Torres
This article develops a general thermodynamic treatment to predict the direction of shift in a chemical equilibrium when it is subjected to a stress. This treatment gives an inequality that relates the change in the perturbed variable and the change that the equilibrium shift produces in the conjugated variable.
Torres, Emilio Martínez. J. Chem. Educ. 2007, 84, 516.
Equilibrium |
Reactions |
Thermodynamics
Biodiesel Synthesis and Evaluation: An Organic Chemistry Experiment  Ehren C. Bucholtz
In this two week lab sequence students synthesize fatty acid methyl esters from simulated waste vegetable oil and determine whether the glycerol concentration of the resulting product is low enough to meet the specifications for marketable biodiesel.
Bucholtz, Ehren C. J. Chem. Educ. 2007, 84, 296.
Equilibrium |
Esters |
Industrial Chemistry |
Lipids |
Quantitative Analysis
A Test Construction Support System for Chemistry Teachers  Derek Cheung
Describes Windows-compatible software to help teachers to implement formative assessment in secondary-school chemistry. The computer-based environment can be used to create Web-based multiple-choice items for students to self-assess their learning of chemistry.
Cheung, Derek. J. Chem. Educ. 2006, 83, 1399.
Acids / Bases |
Electrochemistry |
Equilibrium |
Professional Development
Achieving Chemical Equilibrium: The Role of Imposed Conditions in the Ammonia Formation Reaction  Joel Tellinghuisen
The conditions under which chemical reactions occur determine which thermodynamic functions are minimized or maximized. This point is illustrated for the formation of ammonia in the ideal gas approximation using a numerical exercise.
Tellinghuisen, Joel. J. Chem. Educ. 2006, 83, 1090.
Gases |
Equilibrium |
Thermodynamics
Give Them Money: The Boltzmann Game, a Classroom or Laboratory Activity Modeling Entropy Changes and the Distribution of Energy in Chemical Systems  Robert M. Hanson and Bridget Michalek
Described here is a short, simple activity that can be used in any high school or college chemistry classroom or lab to explore the way energy is distributed in real chemical systems and as an entry into discussions of the probabilistic nature of entropy.
Hanson, Robert M.; Michalek, Bridget. J. Chem. Educ. 2006, 83, 581.
Equilibrium |
Statistical Mechanics |
Thermodynamics
Modeling Dynamic Equilibrium with Coins  Martin Bartholow
Students explore the concept of equilibrium by moving small objects between two piles.
Bartholow, Martin. J. Chem. Educ. 2006, 83, 48A.
Computational Chemistry |
Equilibrium |
Rate Law
Using Computer Simulations To Teach Salt Solubility. The Role of Entropy in Solubility Equilibrium  Victor M. S. Gil and João C. M. Paiva
Pairs of salts are discussed to illustrate the interpretation of their different behavior in water in terms of the fundamental concept of entropy. The ability of computer simulations to help improve students' understanding of these chemistry concepts is also examined.
Gil, Victor M. S.; Paiva, João C. M. J. Chem. Educ. 2006, 83, 170.
Computational Chemistry |
Equilibrium |
Thermodynamics |
Solutions / Solvents |
Precipitation / Solubility
The Ammonia Synthesis Reaction: An Exception to the Le Châtelier Principle and Effects of Nonideality  Mark J. Uline and David S. Corti
The ammonia synthesis reaction exhibits a well-known exception to Le Chtelier's principle. The mole fraction of nitrogen at which the reaction shifts direction (upon the addition of more nitrogen) is found to be strongly dependent upon the temperature and pressure.
Uline, Mark J.; Corti, David S. J. Chem. Educ. 2006, 83, 138.
Equilibrium |
Reactions |
Thermodynamics
Equilibria That Shift Left upon Addition of More Reactant  Jeffrey E. Lacy
Most textbook presentations of Le Chtelier's principle in general and physical chemistry do not include a discussion of constant pressure conditions for which addition of a reactant can shift the equilibrium to the left. We propose presentations of isothermal, open systems at constant pressure for both levels of study by using concepts and skills that the respective students already possess. In addition, we derive novel criteria based on the stoichiometry of the reaction that can be used to identify those equilibria that will shift left upon addition of more reactant.
Lacy, Jeffrey E. J. Chem. Educ. 2005, 82, 1192.
Equilibrium |
Mathematics / Symbolic Mathematics |
Thermodynamics
Microscopic Description of Le Châtelier's Principle  Igor Novak
The analysis based on microscopic descriptors (energy levels and their populations) is given that provides visualization of free energies and conceptual rationalization of Le Châtelier's principle. The misconception "nature favors equilibrium" is highlighted.
Novak, Igor. J. Chem. Educ. 2005, 82, 1190.
Equilibrium |
Thermodynamics
The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems  Paul S. Matsumoto
While my paper states that the reaction quotient (Q) is not needed to solve equilibrium problems, it does not imply that Q is not valuable. In fact, when I teach this topic to my AP chemistry class, I initially use Q to solve the problem, then mention the alternative method described in the paper.
Matsumoto, Paul S. J. Chem. Educ. 2005, 82, 1150.
Equilibrium |
Learning Theories |
Mathematics / Symbolic Mathematics
The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems: No Problems with Q  Robert Lederer
Mr. Matsumotos students are to be congratulated for discerning an interesting mathematical procedure. Exclusively utilizing this algorithm, however, short-cuts the understanding of the chemistry involved. Students of chemistry should be challenged to understand why something occurs, and not to be satisfied with how to perform the often mundane calculations.
Lederer, Robert. J. Chem. Educ. 2005, 82, 1149.
Equilibrium |
Mathematics / Symbolic Mathematics
The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems: The Reaction Quotient (Q) IS Useful After All  Todd P. Silverstein
Paul Matsumoto was absolutely correct in writing The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems.
Silverstein, Todd P. J. Chem. Educ. 2005, 82, 1149.
Equilibrium |
Thermodynamics
The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems: The Reaction Quotient (Q) IS Useful After All  Todd P. Silverstein
Paul Matsumoto was absolutely correct in writing The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems.
Silverstein, Todd P. J. Chem. Educ. 2005, 82, 1149.
Equilibrium |
Thermodynamics
Putting A Human Face on Equilibrium  Neil Glickstein
A short biography of chemist Fritz Haber is used to personalize the abstract concepts of equilibrium chemistry for high school students in an introductory course. In addition to giving the HaberBosch process an historic, an economic, and a scientific background the reading and subsequent discussion allows students for whom the human perspective is of paramount importance a chance to investigate the irony of balance or equilibrium in Haber's life story.
Glickstein, Neil. J. Chem. Educ. 2005, 82, 391.
Equilibrium
Using Clinical Cases To Teach General Chemistry  Brahmadeo Dewprashad, Charles Kosky, Geraldine S. Vaz, and Charlotte L. Martin
This article describes how a fact-based clinical case was effectively used to motivate and enrich the classroom experience and review many of the concepts covered in general chemistry. The case involves an elderly patient who was brought to the emergency room. The results of his physical examination and laboratory analysis of his blood are presented. The students, in peer-led groups, work through the chemical principles involved in the doctor's diagnosis and treatment options for the patient. The article describes the case study, instructors' observations, and students' perception of the activity.
Dewprashad, Brahmadeo; Kosky, Charles; Vaz, Geraldine S.; Martin, Charlotte L. J. Chem. Educ. 2004, 81, 1471.
Acids / Bases |
Drugs / Pharmaceuticals |
Equilibrium |
Kinetics |
Medicinal Chemistry
Playing-Card Equilibrium  Robert M. Hanson
A simple hands-on simulation suitable for either classroom use or laboratory investigation involves using a standard deck of playing cards to explore the statistical aspects of equilibrium. Concepts that can be easily demonstrated include fluctuation around a most probable distribution, Le Chtelier's principle, the equilibrium constant, prediction of the equilibrium constant based on probability, and the effect of sample size on equilibrium fluctuations.
Hanson, Robert M. J. Chem. Educ. 2003, 80, 1271.
Equilibrium |
Statistical Mechanics |
Thermodynamics
Approaches to the Treatment of Equilibrium Perturbations  Sebastian G. Canagaratna
Perturbations from equilibrium are treated in the textbooks by a combination of Le Chtelier's principle, the comparison of the equilibrium constant K with the reaction quotient Q,and the kinetic approach. Each of these methods is briefly reviewed. This is followed by derivations of the variation of the equilibrium value of the extent of reaction, ?eq, with various parameters on which it depends.
Canagaratna, Sebastian G. J. Chem. Educ. 2003, 80, 1211.
Equilibrium |
Thermal Analysis |
Thermodynamics
Le Chat: Simulation in Chemical Equilibrium  João C. M. Paiva, Victor M. S. Gil, and António Ferrer Correia
Software that illustrates Le Chatelier's principle; found on the Advanced Chemistry Collection CD-ROM, 3rd Edition.
Paiva, João C. M.; Gil, Victor M. S.; Correia, António Ferrer. J. Chem. Educ. 2003, 80, 111.
Equilibrium
Rubber Bands, Free Energy, and Le Châtelier's Principle  Warren Hirsch
Using a rubber band to illustrate Gibbs free energy, entropy, and enthalpy.
Hirsch, Warren. J. Chem. Educ. 2002, 79, 200A.
Noncovalent Interactions |
Thermodynamics |
Equilibrium
Le Chat: Simulation in Chemical Equilibrium  João C. M. Paiva, Victor M. S. Gil, and António Ferrer Correia

João C. M. Paiva; Gil, Victor M. S.; Correia, António Ferrer Correia. J. Chem. Educ. 2002, 79, 640.
Equilibrium
The Mechanism of Aqueous Hydrolysis of Nitro Derivatives of Phenyl Phenylmethanesulfonate. An Organic Laboratory Experiment  S. D. Mulder, B. E. Hoogenboom, and A. G. Splittgerber
Synthesis, purification, and characterization of three esters.
Mulder, S. D.; Hoogenboom, B. E.; Splittgerber, A. G. J. Chem. Educ. 2002, 79, 218.
Mechanisms of Reactions |
Molecular Properties / Structure |
Resonance Theory |
Reactive Intermediates |
Equilibrium |
Esters |
Aromatic Compounds |
Brønsted-Lowry Acids / Bases
Assessing Students' Conceptual Understanding of Solubility Equilibrium  Andrés Raviolo
A problem about solubility equilibrium is presented as a resource for the evaluation of students; it involves macroscopic, microscopic, and symbolic levels of representation, and allows one to assess whether students have acquired an adequate conceptual understanding of the phenomenon.
Raviolo, Andrés. J. Chem. Educ. 2001, 78, 629.
Kinetic-Molecular Theory |
Equilibrium |
Precipitation / Solubility
The State of Division of Solids and Chemical Equilibria  João C. M. Paiva and Victor M. S. Gil
An experiment and a computer simulation are presented to address a counterintuitive situation often encountered when teaching chemical equilibria. This is prompted by the question "How can the subdivision of a solid reactant affect the reaction rate and not the composition of the equilibrium state?"
Paiva, João C. M.; Gil, Victor M. S. J. Chem. Educ. 2001, 78, 222.
Equilibrium |
Kinetics |
Laboratory Computing / Interfacing
Modification of Small-Scale One-Pot Reactions to an Inquiry-Based Laboratory Exercise  C. Jayne Wilcox
Students are given an initial handout and asked to complete a short, attention-getting exercise. They must continue to work on logical, short exercises given to them one at a time, in handout format. The inquiry-based approach is intended to increase students' comprehension of what they're doing in the laboratory and why.
Wilcox, C. Jayne. J. Chem. Educ. 2001, 78, 62.
Acids / Bases |
Aqueous Solution Chemistry |
Precipitation / Solubility |
Equilibrium
Understanding, Deriving, and Computing Buffer Capacity  Edward T. Urbansky and Michael R. Schock

Urbansky, Edward T.; Schock, Michael R. J. Chem. Educ. 2000, 77, 1640.
Acids / Bases |
Equilibrium |
Water / Water Chemistry
The Complexity of Teaching and Learning Chemical Equilibrium (about J. Chem. Educ., 1999, 76, 554-558 )  David Treagust

Treagust, David. J. Chem. Educ. 2000, 77, 1560.
Equilibrium |
Learning Theories
The Complexity of Teaching and Learning Chemical Equilibrium (about J. Chem. Educ., 1999, 76, 554-558)  João C. M. Paiva and Victor M. S. Gil

Paiva, João C. M.; Gil, Victor M. S. J. Chem. Educ. 2000, 77, 1560.
Equilibrium |
Learning Theories
Simulating Dynamic Equilibria: A Class Experiment  John A. Harrison and Paul D. Buckley
A first-order reversible reaction is simulated on an overhead projector using small coins or discs. Results illustrate how dynamic equilibria are established and allow the introduction of the concept of an equilibrium constant. Le Chtelier's principle is illustrated by further simulations.
Harrison, John A.; Buckley, Paul D. J. Chem. Educ. 2000, 77, 1013.
Equilibrium |
Rate Law |
Reactions
Simulations for Teaching Chemical Equilibrium  Penelope A. Huddle, Margaret Dawn White, and Fiona Rogers
This paper outlines a systematic approach to teaching chemical equilibrium using simulation experiments that address most known alternate conceptions in the topic. Graphs drawn using the data from the simulations are identical to those obtained using real experimental data for reactions that go to equilibrium. This allows easy mapping of the analogy to the target.
Huddle, Penelope Ann; White, Margaret Dawn; Rogers, Fiona. J. Chem. Educ. 2000, 77, 920.
Equilibrium |
Learning Theories
The Complexity of Teaching and Learning Chemical Equilibrium  Louise Tyson, David F. Treagust, and Robert B. Bucat
This paper discusses three key issues relevant to secondary school chemistry teaching. They arise from a study of students' understanding of chemical equilibrium using qualitative and quantitative research methods.
Tyson, Louise; Treagust, David F.; Bucat, Robert B. J. Chem. Educ. 1999, 76, 554.
Equilibrium |
Learning Theories
Potential Functions in Chemical Thermodynamics  Roger Araujo
The first and second laws of thermodynamics are stated in equation form. The equation containing the combined laws is used to identify potential functions appropriate to various sets of constraints. An ion-exchange reaction and a redox reaction in a melt are considered as illustrations of the importance of using the potential function appropriate to the constraints.
Araujo, Roger. J. Chem. Educ. 1998, 75, 1490.
Thermodynamics |
Equilibrium |
Oxidation / Reduction |
Ion Exchange
The Microscale Synthesis and Electrochemistry of Low-Valent Mononuclear Complexes (?3-C3H5)Fe(CO)3 X (X = I, Br, Cl)  Enrico Mocellin, Richard Russell, and Mauro Ravera
By combining experimental procedures which place microscale, chemical synthesis, and an inclusive, unified, product characterization in perspective, we have afforded the student the scope to obtain progressive, disciplined results and the opportunity to discuss these in the subsequent reporting.
Mocellin, Enrico; Russell, Richard; Ravera, Mauro. J. Chem. Educ. 1998, 75, 773.
Organometallics |
Microscale Lab |
Electrochemistry |
Synthesis
The Temperature Dependence of DeltaG° and the Equilibrium Constant, Keq; Is There a Paradox?  Frances H. Chapple
Why the temperature-dependence of the equilibrium constant of a reaction is determined by the sign and value of ?H, whereas the temperature-dependence of ?G of a reaction is determined by the sign and value of ?S.
Chapple, Frances H. J. Chem. Educ. 1998, 75, 342.
Equilibrium |
Thermodynamics
Thermal Coefficients and Heat Capacities in Systems with Chemical Reaction: The Le Chtelier-Braun Principle  Guemez, J.; Velasco, S.; Matias, M. A.
Discussion of the way in which the occurrence of a chemical reaction affects the response of a system against external mechanical or thermal perturbations with respect to the Le Chtelier-Braun principle.
Guemez, J.; Velasco, S.; Matias, M. A. J. Chem. Educ. 1995, 72, 199.
Equilibrium |
Calorimetry / Thermochemistry |
Thermodynamics
Chemical equilibrium: I. The thermodynamic equilibrium constant  Gordus, Adon A.
This is the first article in a series of eight that investigates the various assumptions that result in the simplified equilibrium equations found in most introductory texts. In this first article, the author considers the general nature of the constant K, Le Chatelier's principle, and the effect of the temperature on K.
Gordus, Adon A. J. Chem. Educ. 1991, 68, 138.
Thermodynamics |
Equilibrium
Student ideas regarding chemical equilibrium: What written test answers do not reveal  Bergquist, Wilbur; Heikkinen, Henry
Examples, evidence, and implications of student misconceptions regarding chemical equilibrium.
Bergquist, Wilbur; Heikkinen, Henry J. Chem. Educ. 1990, 67, 1000.
Equilibrium |
Constructivism
Effects of "crowding" in protein solutions  Ralston, G. B.
The effects of macromolecular nonideality and crowding on chemical equilibria, association reactions, and enzyme kinetics.
Ralston, G. B. J. Chem. Educ. 1990, 67, 857.
Proteins / Peptides |
Equilibrium |
Reactions |
Enzymes |
Kinetics
Teaching freezing point lowering  Ball, Jenelle; Cooke, Ron C.; Willis, Grover
Using Le Chatelier's principle, the van't Hoff equation, and the empirical equation to explain the lowering of the freezing point caused by dissolving antifreeze in water.
Ball, Jenelle; Cooke, Ron C.; Willis, Grover J. Chem. Educ. 1990, 67, 676.
Physical Properties |
Solutions / Solvents |
Equilibrium |
Aqueous Solution Chemistry
Computer simulation of chemical equilibrium  Cullen, John F., Jr.
108. The "Great Chemical Bead Game" requires no instruments and presents the concepts of equilibrium and kinetics more clearly than an experiment. [October and November Computer Series both inadvertently called number 107. Numbering restored by skipping 109 and calling January 1990 number 110.]
Cullen, John F., Jr. J. Chem. Educ. 1989, 66, 1023.
Equilibrium |
Kinetics |
Rate Law
For or Against Le Chtelier?  Logan, S. R.
In your June 1988 issue that contained on p. 482 a most cogent statement of the reasons why we should never again mention the (non-) principle of Le Chtelier, you give that subject an honorable mention on p. 588!
Logan, S. R. J. Chem. Educ. 1989, 66, 360.
Equilibrium
Le Chtelier and chemical equilibrium   Ihde, John
The reader is encouraged to view Le Chtelier's principle not as simply a chemical phenomenon to be used in explaining what happened in numerous "dry" chemical reactions.
Ihde, John J. Chem. Educ. 1989, 66, 238.
Equilibrium
Phase equilibrium and G minimum: Displacements of the equilibrium under external parameters  Deumie, M.; Henri-Rousseau, O.; Boulil, K.; Boulil, B.
The object of this paper is to treat the displacement of a phase equilibrium with respect to changes in pressure, temperature, amount of solute, and amount of an inert gas, in the framework of the Perona approach.
Deumie, M.; Henri-Rousseau, O.; Boulil, K.; Boulil, B. J. Chem. Educ. 1989, 66, 232.
Phases / Phase Transitions / Diagrams |
Equilibrium
Temperature and concentration dependence of homogeneous chemical equilibria   Smith, C. Brent
A test or homework problem that allows for the presentation of many concepts in a situation of commercial importance.
Smith, C. Brent J. Chem. Educ. 1988, 65, 965.
Equilibrium |
Heterocycles |
Thermodynamics
Experimental work with tin(II) chloride in a high school   Sanchez, Manuela Martin
The author describes a final-project performed by students that integrates concepts of hydrolysis, Le Chatelier's principle, and electrolysis. Students seek answers to questions such as: "What reactions were involved; why is an aqueous solution of SnCl2 acidic; how can elemental tin be recovered from the system?"
Sanchez, Manuela Martin J. Chem. Educ. 1988, 65, 898.
Separation Science |
Electrochemistry |
Electrolytic / Galvanic Cells / Potentials |
Equilibrium |
Oxidation / Reduction
Simple models for teaching equilibrium and Le Chtelier's principle   Russell, Joan M.
This article presents three models that have been effective in teaching chemical equilibrium and Le Chtelier's Principle: 1) the liquid transfer model, 2) the fish model, and 3) the teeter-totter model.
Russell, Joan M. J. Chem. Educ. 1988, 65, 871.
Equilibrium
Tools of the trade   Bruno, Michael J.
High school teachers can never have too many visual aids when teaching chemistry. This author shares some demonstrations in equilibrium that often produce "oohs" and "aaaahs" from his students.
Bruno, Michael J. J. Chem. Educ. 1988, 65, 698.
Equilibrium |
pH
The effect of temperature and pressure on equilibria: A derivation of the van't Hoff rules  Kemp, H. R.
Derivation of the van't Hoff rules for disturbed equilibria.
Kemp, H. R. J. Chem. Educ. 1987, 64, 482.
Equilibrium |
Thermodynamics
Le Chtelier's principle, solubility, and deja vu  Jensen, William B.
Succeeding generations of textbooks are based more and more on those of the past and, in the process, are gradually simplified and idealized until in some cases they are simply incorrect.
Jensen, William B. J. Chem. Educ. 1987, 64, 287.
Equilibrium
On the minimum of the Gibbs free energy involved in chemical equilibrium  Deumie, M.; Boulil, B.; Henri Rousseau, O.
Proposal of a new approach to chemical equilibrium in order to narrow the gap between introductory teaching and texts that deal with irreversible processes.
Deumie, M.; Boulil, B.; Henri Rousseau, O. J. Chem. Educ. 1987, 64, 201.
Equilibrium |
Thermodynamics
Further observations on the cobalt(II)-chloride equilibrium: Effect of changing the chloride ion concentration  Martins, Luis J. A.; da Costa, J. Barbosa
In this article, the authors supplement previous experiments on equilibrium by confirming the effect of changes in chloride ion concentration.
Martins, Luis J. A.; da Costa, J. Barbosa J. Chem. Educ. 1986, 63, 989.
Equilibrium |
Coordination Compounds |
Acids / Bases
A demonstration of equilibrium   Bricker, Clark E.
Demonstrations with iron (III) nitrate nonanhydrate illustrate Le Chatelier's principle and also produce some unexpected results.
Bricker, Clark E. J. Chem. Educ. 1986, 63, 979.
Equilibrium
A better way of dealing with chemical equilibrium   Tykodi, Ralph J.
The activity concept is important in modern physical chemistry and thermodynamics, but it is rarely discussed in textbooks.
Tykodi, Ralph J. J. Chem. Educ. 1986, 63, 582.
Equilibrium |
Thermodynamics
Le Châtelier's Principle  Knox, Kerro
Question involving effect of increasing the pressure on the N2 + 3H2 <=> 2NH3 system.
Knox, Kerro J. Chem. Educ. 1985, 62, 863.
Equilibrium |
Gases
Le Chtelier - Right or wrong? Optimizing chemical reaction equilibria  Helfferich, Friedrich G.
Questions to determine student understanding of the mass action law and Le Chtelier's principle as applied to chemical reaction equilibria.
Helfferich, Friedrich G. J. Chem. Educ. 1985, 62, 305.
Equilibrium
Le Châtelier's principle, temperature effects, and entropy  Campbell, J. Arthur
A useful extension of Le Chatelier's Principle to predict concentration, pressure, and temperature effects solely from the equation for the net reaction.
Campbell, J. Arthur J. Chem. Educ. 1985, 62, 231.
Equilibrium |
Thermodynamics
Le Chtelier's principle applied to the temperature dependence of solubility  Treptow, Richard S.
Tests Le Chtelier's principle for predicting the temperature dependence of solubility for ionic compounds in water.
Treptow, Richard S. J. Chem. Educ. 1984, 61, 499.
Precipitation / Solubility |
Solutions / Solvents |
Equilibrium |
Aqueous Solution Chemistry |
Thermodynamics
Cobalt complexes and Le Châtelier  Grant, A. Ward, Jr.
The cobalt complexes are an excellent demonstration to illustrate Le Châtelier's Principle to beginning chemistry students.
Grant, A. Ward, Jr. J. Chem. Educ. 1984, 61, 466.
Coordination Compounds |
Equilibrium
Cooking with chemistry  Grosser, Arthur E.
Two demonstrations involving cooking eggs and suggestions for many more examples of cooking that illustrate important principles of chemistry. From the "State-of-the-Art Symposium for Chemical Educators: Chemistry of the Food Cycle".
Grosser, Arthur E. J. Chem. Educ. 1984, 61, 362.
Food Science |
Gases |
Acids / Bases |
Equilibrium |
Kinetics
Le Châtelier's principle: the effect of temperature on the solubility of solids in liquids  Brice, L. K.
The purpose of this article is to provide a rigorous but straightforward thermodynamic treatment of the temperature dependence of solubility of solids in liquids that is suitable for presentation at the undergraduate level. The present discussion may suggest how to approach the qualitative aspects of the subject for freshman.
Brice, L. K. J. Chem. Educ. 1983, 60, 387.
Thermodynamics |
Liquids |
Solids |
Chemometrics |
Equilibrium
Le Chtelier's principle, coupled equilibrium, and egg shells  Brown, David B.; MacKay, III, John A.
Hot chickens have economic implications that can be better understood through chemistry.
Brown, David B.; MacKay, III, John A. J. Chem. Educ. 1983, 60, 198.
Equilibrium |
Applications of Chemistry |
Food Science |
Agricultural Chemistry
Real-time computer simulation of aqueous equilibrium   Schilling, J. W.
36. Bits and pieces, 13. The computer program described in this article illustrates that a model based on simple kinetic arguments explains why the reaction quotient approaches a constant value called the equilibrium constant. It has both qualitative and quantitative fidelity to the actual chemical process.
Schilling, J. W. J. Chem. Educ. 1983, 60, 43.
Thermodynamics |
Kinetics |
Equilibrium
Le Chtelier's principle and the prediction of the effect of temperature on solubilities  Fernandez-Prini, R.
Reflects of some statements and conclusions of the cited article and analyzes Le Chtelier's principle from a more general, thermodynamic perspective.
Fernandez-Prini, R. J. Chem. Educ. 1982, 59, 550.
Precipitation / Solubility |
Solutions / Solvents |
Liquids |
Gases |
Equilibrium |
Thermodynamics
Using the equilibrium concept   Mickey, Charles D.
Equilibrium in systems is an important concept in organic, biochemical, and industrial chemistry among others.
Mickey, Charles D. J. Chem. Educ. 1981, 58, 56.
Biophysical Chemistry |
Equilibrium |
Esters |
Molecular Biology |
Kinetics |
Oxidation / Reduction |
Aqueous Solution Chemistry
Chemical equilibrium  Mickey, Charles D.
The law of mass action, the equilibrium constant, and the effect of temperature, concentration, and pressure on equilibrium.
Mickey, Charles D. J. Chem. Educ. 1980, 57, 801.
Equilibrium |
Catalysis
Le Châtelier's principle: A reexamination and method of graphic illustration  Treptow, Richard S.
Le Châtelier's development of the principle that bears his name, and a rephrasing of that principle to make it technically and historically accurate.
Treptow, Richard S. J. Chem. Educ. 1980, 57, 417.
Equilibrium
A chemistry lesson at Three Mile Island  Mammano, Nicholas J.
Teaching principles of general chemistry through references made to the nuclear incident at Three Mile Island.
Mammano, Nicholas J. J. Chem. Educ. 1980, 57, 286.
Equilibrium |
Gases |
Stoichiometry |
Nonmajor Courses |
Nuclear / Radiochemistry |
Applications of Chemistry
On the misuse of Le Châtelier's principle for the prediction of the temperature dependence of the solubility of salts  Bodner, George M.
Explores why Le Châtelier's principle often fails to predict the temperature dependence of the solubility of salts.
Bodner, George M. J. Chem. Educ. 1980, 57, 117.
Equilibrium |
Precipitation / Solubility |
Solutions / Solvents |
Aqueous Solution Chemistry
Coupled phenomena in chemistry: Understanding of chemistry through Gibbs energy utilization  Nomura, Kazuo; Matsubara, Akira
Provides examples of coupled reactions and the utilization of Gibbs energy in a variety of chemical processes.
Nomura, Kazuo; Matsubara, Akira J. Chem. Educ. 1979, 56, 718.
Thermodynamics |
Acids / Bases |
Oxidation / Reduction |
Equilibrium
The temperature dependence of the equilibrium constant  Burness, James H.
This exam question tests a student's ability to derive the temperature dependence of an equilibrium constant not by qualitatively applying Le Chatelier's principle, but by understanding the relationship between the kinetics of the equation and the value of Keq.
Burness, James H. J. Chem. Educ. 1979, 56, 395.
Equilibrium |
Kinetics
An apparent contradiction in the application of the principle of Le Chtelier  Mellon, E. K.
Unless some care is exercised, the application of free energy concepts in situations where marked temperature changes occur can lead to apparent contradictions like the one described in this paper.
Mellon, E. K. J. Chem. Educ. 1979, 56, 380.
Equilibrium |
Thermodynamics
High pressure synthetic chemistry  Hagen, Arnult P.
The use of pressure in excess of 200atm is not common in synthesis or instructional laboratories even though fittings and commercial apparatus are available. This paper describes several experimental results selected from typical inorganic and organic reaction systems along with a brief description of the physical parameters needed to determine if a pressure increase will help solve a synthetic problem.
Hagen, Arnult P. J. Chem. Educ. 1978, 55, 620.
Laboratory Equipment / Apparatus |
Laboratory Management |
Equilibrium |
Kinetics
Chemical equilibrium: Analogies that separate the mathematics from the chemistry  DeLorenzo, Ronald A.
Demonstrates that the mathematics of chemical equilibria are not difficult, particularly when put in a non-chemical context.
DeLorenzo, Ronald A. J. Chem. Educ. 1977, 54, 676.
Equilibrium |
Chemometrics
Le Chtelier's principle: A laboratory exercise  Friedman, Frederica
Le Chtelier's principle can be demonstrated by showing that water can boil at temperatures below 100C due to reduced vapor pressure.
Friedman, Frederica J. Chem. Educ. 1977, 54, 236.
Equilibrium |
Phases / Phase Transitions / Diagrams |
Gases |
Water / Water Chemistry
On mole fractions in equilibrium constants  Delaney, C. M.; Nash, Leonard K.
Proposes a hybrid equilibrium constant for use in introductory chemistry courses.
Delaney, C. M.; Nash, Leonard K. J. Chem. Educ. 1977, 54, 151.
Equilibrium |
Stoichiometry |
Aqueous Solution Chemistry |
Solutions / Solvents
A dynamic lecture demonstration of dynamic equilibrium - The BG system  Battino, Rubin
This demonstration uses students as atoms and molecules.
Battino, Rubin J. Chem. Educ. 1975, 52, 55.
Equilibrium
Untitled letter  Macomber, Roger S.
Published experimental data is correct, and this writer defends the conclusions he made about the data after several readers raised questions.
Macomber, Roger S. J. Chem. Educ. 1974, 51, 555.
Equilibrium
Lecture experiment: A quantitative illustration of LeChatelier's principle  Nelson, D. L.; Ginns, E. I.; Richtol, H. H.; Reeves, R. R.
A short experiment involving the popular gaseous nitrogen dioxide system has been developed into a lecture demonstration which quantitatively illustrates the behavior of a homogeneous gas-phase equilibrium under conditions of varying temperature and pressure.
Nelson, D. L.; Ginns, E. I.; Richtol, H. H.; Reeves, R. R. J. Chem. Educ. 1973, 50, 721.
Equilibrium |
Gases
The solubility of sodium acetate in water and LeChatelier's principle  Mazo, Robert M.; Barnhard, Ralph
Resolves the apparent anomaly between the solubility of anhydrous sodium acetate in water as a function of temperature and the exothermic nature of this process.
Mazo, Robert M.; Barnhard, Ralph J. Chem. Educ. 1972, 49, 639.
Water / Water Chemistry |
Aqueous Solution Chemistry |
Solutions / Solvents |
Equilibrium |
Calorimetry / Thermochemistry |
Thermodynamics
The design and use of an equilibrium machine  Alden, Robert T.; Schmuckler, Joseph S.
An operating model that can be used to determine quantitatively equilibrium shifts when demonstrating Le Chatelier's Principle and relates to molecular level considerations and the probabilistic nature of equilibrium.
Alden, Robert T.; Schmuckler, Joseph S. J. Chem. Educ. 1972, 49, 509.
Equilibrium
The chemistry of a cooling drink  Albrecht, Gustav
Explanation for why ice cubes fuse.
Albrecht, Gustav J. Chem. Educ. 1972, 49, 146.
Phases / Phase Transitions / Diagrams |
Equilibrium
Gas Laws, Equilibrium, and the Commercial Synthesis of Nitric acid. A Simple Demonstration  Alexander, M. Dale
This demonstration of the commercial production of nitric acid uses a simple apparatus to illustrate a number of basic chemical concepts, including Le Chatelier's principle.
Alexander, M. Dale J. Chem. Educ. 1971, 48, 838.
Synthesis |
Industrial Chemistry |
Acids / Bases |
Gases |
Equilibrium |
Reactions |
Stoichiometry
Quantitative studies of conformational energies in some cyclic compounds  Wyn-Jones, E.
The authors discuss methods that have proved to be versatile in determining conformational energies especially in heterocyclic molecules and in this article the principles involved in these methods and some complimentary results will be discussed.
Wyn-Jones, E. J. Chem. Educ. 1971, 48, 402.
Alkanes / Cycloalkanes |
Thermodynamics |
Constitutional Isomers |
NMR Spectroscopy |
Equilibrium
Coordination complexes and equilibrium  Shombert, Donald J.
The results of this demonstration are explained in terms of equilibrium, Le Chatelier-Braun's principle, and coordination complex formation.
Shombert, Donald J. J. Chem. Educ. 1970, 47, A784.
Coordination Compounds |
Equilibrium |
Aqueous Solution Chemistry
Le Chtelier's principles - Conductivity of solutions  Kasimer, Philip
Observing conductivity of a dilute solution of glacial acetic acid before and after the addition of a magnesium ribbon.
Kasimer, Philip J. Chem. Educ. 1970, 47, A439.
Equilibrium |
Electrochemistry |
Aqueous Solution Chemistry
Demonstrating the relation between rate constants and the equilibrium constant  Meyer, Edwin F.; Glass, Edward
Presents an approach used with an apparatus to demonstrate quantitatively the relationship between rate constants and the equilibrium constant for simple reversible reactions.
Meyer, Edwin F.; Glass, Edward J. Chem. Educ. 1970, 47, 646.
Rate Law |
Equilibrium |
Reactions
Component concentrations in solutions of weak acids  Goldish, Dorothy M.
presents a new approach to teaching the subject of weak acid equilibria and its associated calculations.
Goldish, Dorothy M. J. Chem. Educ. 1970, 47, 65.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
Chemometrics |
pH
Le Chtelier's principle  Melott, Adrian L.
Adding a strong base to aqueous ammonia causes gaseous ammonia to be released.
Melott, Adrian L. J. Chem. Educ. 1968, 45, A519.
Equilibrium |
Solutions / Solvents |
Precipitation / Solubility |
Acids / Bases |
Aqueous Solution Chemistry
Le Chtelier and ionic equilibria  Ringbom, Anders
When s solution contains several weak acids, the squares of the separately calculated hydrogen ion concentrations of all weak acids in the solution are additive.
Ringbom, Anders J. Chem. Educ. 1968, 45, 442.
Equilibrium |
Acids / Bases |
Precipitation / Solubility |
Solutions / Solvents
Le Chtelier's principle and rigorous ionic equilibria equations  Goldman, James A.
Presents an approach, exemplified by acid-base and solubility equilibria, that relates the concept of Le Chtelier's principle to rigorous ionic equilibria equations.
Goldman, James A. J. Chem. Educ. 1967, 44, 658.
Equilibrium |
Acids / Bases |
Aqueous Solution Chemistry
Principles of chemical equilibrium (Morris, Kelso B.)  Eblin, Lawrence P.

Eblin, Lawrence P. J. Chem. Educ. 1966, 43, 110.
Equilibrium |
Enrichment / Review Materials
Concerning equilibrium, free energy changes, LeChatelier's Principle. III. Halide-halate equilibria  Eberhardt, William H.
Compares four equilibria: KI + KIO3, KI + KBrO3, KBR + KBrO3, and KBr + KIO3.
Eberhardt, William H. J. Chem. Educ. 1964, 41, A883.
Equilibrium |
Aqueous Solution Chemistry |
Thermodynamics
Concerning equilibrium, free energy changes, Le Châtelier's principle II  Eberhardt, William H.
This demonstration involves a reversible, temperature-based transformation from blue tetrahedrally coordinated Co2+ to pink sixfold coordinated Co2+.
Eberhardt, William H. J. Chem. Educ. 1964, 41, A591.
Equilibrium |
Thermodynamics |
Aqueous Solution Chemistry |
Coordination Compounds
Concerning equilibrium, free energy changes, Le Chtelier's principle  Eberhardt, William H.
Aqueous KI is added to a solution of CuSO4 in a separatory funnel; adding more CuSO4 demonstrates an equilibrium sift.
Eberhardt, William H. J. Chem. Educ. 1964, 41, A477.
Equilibrium |
Thermodynamics |
Reactions
A model for demonstrating dynamic equilibria  Weigang, O. E., Jr.
Presents an apparatus for demonstrating dynamic equilibrium.
Weigang, O. E., Jr. J. Chem. Educ. 1962, 39, 146.
Equilibrium
A systematic way to avoid Le Chtelier's principle in chemical reactions  Katz, Lewis
Presents a systematic way to avoid Le Chtelier's principle in chemical reactions.
Katz, Lewis J. Chem. Educ. 1961, 38, 375.
Thermodynamics |
Equilibrium
Apparatus for illustrating Le Châtelier's principle  Tucker, W. C., Jr.
A device consisting of glass tubes and varying levels of water is presented as a means for illustrating equilibrium and Le Châtelier's principle.
Tucker, W. C., Jr. J. Chem. Educ. 1958, 35, 411.
Laboratory Equipment / Apparatus |
Equilibrium
The principle of Le Chtelier and Braun  De Heer, J.
The Le Chtelier-Braun principle made a great impact on the chemistry of the turn of the century, and the possibility of numerous applications gave it a popularity which has persisted to the present.
De Heer, J. J. Chem. Educ. 1957, 34, 375.
Equilibrium |
Thermodynamics
Letters to the editor  Castellan, Gilbert W.
The author presents a simpler method for illustrating the Le Chatelier theorem.
Castellan, Gilbert W. J. Chem. Educ. 1956, 33, 302.
Equilibrium |
Chemometrics
Le Chtelier's theorem  Singh, Bhagat; Ebbing, Darrell
An quantitative analysis of Le Chtelier's theorem.
Singh, Bhagat; Ebbing, Darrell J. Chem. Educ. 1956, 33, 34.
Equilibrium |
Chemometrics
Le Châtelier's principle and the equilibrium constant  Miller, Arild J.
Many students of chemistry have difficulty in understanding how the position of equilibrium in a gaseous reaction can change when the pressure is altered, in accordance with Le Châtelier's principle, without causing a corresponding variation in the equilibrium constant.
Miller, Arild J. J. Chem. Educ. 1954, 31, 455.
Equilibrium |
Reactions |
Gases