| Journal Articles: 30 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
|
Introducing Undergraduate Students to Electrochemistry: A Two-Week Discovery Chemistry Experiment Kenneth V. Mills, Richard S. Herrick, Louise W. Guilmette, Lisa P. Nestor, Heather Shafer, and Mauri A. Ditzler,
Within the framework of a laboratory-focused, guided-inquiry pedagogy, students discover the Nernst equation, the spontaneity of galvanic cells, concentration cells, and the use of electrochemical data to calculate equilibrium constants.
Mills, Kenneth V.; Herrick, Richard S.; Guilmette, Louise W.; Nestor, Lisa P.; Shafer, Heather;Ditzler, Mauri A. J. Chem. Educ. 2008, 85, 1116.
Electrochemistry |
Electrolytic / Galvanic Cells / Potentials |
Equilibrium
|
Configurational Entropy Revisited Frank L. Lambert
Positional entropy should be eliminated from general chemistry instruction and replaced by emphasis on the motional energy of molecules as enabling entropy change.
Lambert, Frank L. J. Chem. Educ. 2007, 84, 1548.
Statistical Mechanics |
Thermodynamics
|
Discovering the Thermodynamics of Simultaneous Equilibria. An Entropy Analysis Activity Involving Consecutive Equilibria Thomas H. Bindel
This activity explores the thermodynamics of simultaneous, consecutive equilibria and is appropriate for second-year high school or AP chemistry. Students discover that a reactant-favored (entropy-diminishing) reaction can be caused to happen if it is coupled with a product-favored reaction of sufficient entropy production.
Bindel, Thomas H. J. Chem. Educ. 2007, 84, 449.
Acids / Bases |
Equilibrium |
Thermodynamics
|
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
|
The Reaction Quotent Is Unnecessary To Solve Equilibrium Problems. The Limitation of a Qualitative Reasoning—Editor's Note John W. Moore
Discusses the relationship between the concentration of an aqueous solution of acetic acid, its ion concentration, and its equivalent conductance.
Moore, John W. J. Chem. Educ. 2006, 83, 384.
Aqueous Solution Chemistry |
Equilibrium |
Conductivity |
Mathematics / Symbolic Mathematics
|
The Reaction Quotent Is Unnecessary To Solve Equilibrium Problems. The Limitation of a Qualitative Reasoning Rob Lederer
Discusses the relationship between the concentration of an aqueous solution of acetic acid, its ion concentration, and its equivalent conductance.
Lederer, Rob. J. Chem. Educ. 2006, 83, 384.
Aqueous Solution Chemistry |
Equilibrium |
Mathematics / Symbolic Mathematics |
Conductivity
|
The Reaction Quotent Is Unnecessary To Solve Equilibrium Problems. The Limitation of a Qualitative Reasoning Paul Matsumoto
Discusses the relationship between the concentration of an aqueous solution of acetic acid, its ion concentration, and its equivalent conductance.
Matsumoto, Paul. J. Chem. Educ. 2006, 83, 383.
Equilibrium |
Mathematics / Symbolic Mathematics |
Aqueous Solution Chemistry |
Conductivity
|
The Reaction Quotent Is Unnecessary To Solve Equilibrium Problems. The Limitation of a Qualitative Reasoning Michiel Vogelezang
Discusses the relationship between the concentration of an aqueous solution of acetic acid, its ion concentration, and its equivalent conductance.
Vogelezang, Michiel. J. Chem. Educ. 2006, 83, 383.
Aqueous Solution Chemistry |
Equilibrium |
Mathematics / Symbolic Mathematics |
Conductivity
|
The Reaction Quotent Is Unnecessary To Solve Equilibrium Problems. The Limitation of a Qualitative Reasoning Michiel Vogelezang
Discusses the relationship between the concentration of an aqueous solution of acetic acid, its ion concentration, and its equivalent conductance.
Vogelezang, Michiel. J. Chem. Educ. 2006, 83, 383.
Aqueous Solution Chemistry |
Equilibrium |
Mathematics / Symbolic Mathematics |
Conductivity
|
Equilibria That Shift Left upon Addition of More Reactant Jeffrey E. Lacy
Most textbook presentations of Le Chtelier'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
|
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. Matsumotos 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
|
The Reaction Quotient Is Unnecessary To Solve Equilibrium Problems Paul S. Matsumoto
The traditional method to determine the equilibrium concentration of chemicals in a reaction, given the equilibrium constant and the initial concentration of chemicals in the reaction, involves the determination of the reaction quotient. This article will demonstrate that this step may be eliminated; thereby simplifying the algorithm to solve such problems. Such a reduction in the complexity of the algorithm may result in more students successfully being able to solve such problems.
Matsumoto, Paul S. J. Chem. Educ. 2005, 82, 406.
Equilibrium |
Learning Theories |
Chemometrics
|
Unified Approximations: A New Approach for Monoprotic Weak Acid–Base Equilibria Harry L. Pardue, Ihab N. Odeh, and Teweldemedhin M. Tesfai
This article describes a new approach to approximate calculations for monoprotic acidbase equilibria in otherwise pure water. The new approach, identified herein as unified approximations, uses a simple decision criterion to select between situations that should be treated as deprotonation and protonation reactions. The remaining treatment takes account of changes in concentrations of conjugate acidbase pairs for all situations and ignores autoprotolysis only for situations for which the analytical concentration of either the conjugate acid or conjugate base will always be larger than zero.
Pardue, Harry L.; Odeh, Ihab N.; Tesfai, Teweldemedhin M. J. Chem. Educ. 2004, 81, 1367.
Acids / Bases |
Equilibrium |
Chemometrics
|
Reaction to Why Do We Teach Equilibrium Calculations? Stephen J. Hawkes
"Rigor" in introductory chemistry is often equated with quantitation. Consequently the understanding of chemical reactions and properties is obscured. This was illustrated by Stumpo who asked students to calculate ?E of a reaction, and then on another question on the same test asked a question aimed at its meaning. 77% of the students calculated correctly, but only 24% showed understanding of its meaning. The ability to calculate a number does not measure understanding of the number.
Hawkes, Stephen J. J. Chem. Educ. 2004, 81, 1265.
Equilibrium |
Chemometrics
|
Reaction to Why Do We Teach Equilibrium Calculations? Don L. Lewis
A recently published correspondence by Stephen J. Hawkes on teaching equilibrium calculations troubles me. Hawkes dismisses equilibrium calculations as mere algorithms, best deferred until the student can use computer programs. I find it difficult to believe that a computer program enhances understanding. From a chemists point of view, the equilibrium condition is a limit, a limit that (because of stochastic considerations) does not exist. It might be better to make the reaction quotient statement using < or > but the use of those relations is delayed until quantum mechanics.
Lewis, Don L. J. Chem. Educ. 2004, 81, 1265.
Equilibrium |
Chemometrics
|
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 Chtelier'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
|
The Lead-Acid Battery: Its Voltage in Theory and in Practice Richard S. Treptow
Lead-acid battery fundamentals, cell voltage and the Nernst equation, and an analysis of actual battery performance.
Treptow, Richard S. J. Chem. Educ. 2002, 79, 334.
Electrochemistry |
Oxidation / Reduction |
Thermodynamics |
Electrolytic / Galvanic Cells / Potentials |
Acids / Bases |
Applications of Chemistry
|
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
|
The Nernst Equation: Determination of Equilibrium Constants for Complex Ions of Silver Martin L. Thompson and Laura J. Kateley
The experiment requires a voltmeter capable of recording millivolts (or a good pH meter) and inexpensive chemicals. It allows students to check the validity of the Nernst equation and compare their experimental Kform values to reported ones.
Thompson, Martin L.; Kateley, Laura J. J. Chem. Educ. 1999, 76, 95.
Equilibrium |
Coordination Compounds |
Electrochemistry |
Oxidation / Reduction
|
Teaching Chemical Equilibrium and Thermodynamics in Undergraduate General Chemistry Classes Anil C. Banerjee
Discussion of the conceptual difficulties experienced by undergraduates when dealing with equilibrium and thermodynamics, along with teaching strategies for dealing with these difficulties.
Banerjee, Anil C. J. Chem. Educ. 1995, 72, 879.
Equilibrium |
Thermodynamics
|
Will a precipitate form? Will it dissolve?: The Role of Lecture Demonstrations in Facilitating the Introduction to Solubility Product Equilibria Pacer, Richard A.; Williams, Kathryn
Three demonstrations to illustrate solubility product equilibria.
Pacer, Richard A.; Williams, Kathryn J. Chem. Educ. 1994, 71, 69.
Precipitation / Solubility |
Aqueous Solution Chemistry |
Equilibrium
|
Demonstration of the Common Ion Effect Koubek, E.
KCl and HCl are used in this demonstration to describe the common ion effect and to show the difference between values Q and K.
Koubek, E. J. Chem. Educ. 1993, 70, 155.
Solutions / Solvents |
Equilibrium
|
The acid equilibrium constant is unity! Baldwin, W. G.; Burchill, C. E.
The attempt to assign a non-unity value to this equilibrium constant is a consequence of misunderstanding the way in which the (nearly) constant concentration or activity of the solvent in a dilute solution (or of a pure solid or liquid in a heterogeneous system) is treated when formulating the conventional equilibrium constant expression.
Baldwin, W. G.; Burchill, C. E. J. Chem. Educ. 1992, 69, 514.
Acids / Bases |
Equilibrium |
Aqueous Solution Chemistry
|
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
|
An effective approach to teaching electrochemistry Birss, Viola I.; Truax, D. Rodney
By interweaving concepts from thermodynamics and chemical kinetics with those of electrochemical measurement, the authors provide students with an enriched appreciation of the utility of ideas from kinetics and thermodynamics.
Birss, Viola I.; Truax, D. Rodney J. Chem. Educ. 1990, 67, 403.
Electrochemistry |
Kinetics |
Thermodynamics
|
|
