TIGER

Journal Articles: 366 results
Separation Anxiety: An In-Class Game Designed To Help Students Discover Chromatography  Michael J. Samide
An in-class activity, designed on the basis of plate theory, allows students to physically separate coins on the basis of a provided partition coefficient. Students move coins between stationary and mobile phases to establish equilibrium conditions. The goal is to have students understand equilibration as it relates to separation, which can lead into a discussion of more complex topics.
Samide, Michael J. J. Chem. Educ. 2008, 85, 1512.
Chromatography |
Equilibrium
Using Graphics Calculators and Spreadsheets in Chemistry: Solving Equilibrium Problems   Kieran F. Lim ()
Discusses tabular and graphical approaches to equilibrium calculations.
Lim, Kieran F. (). J. Chem. Educ. 2008, 85, 1347.
Acids / Bases |
Equilibrium
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
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
EQVAPSIM: A Vapor–Liquid Equilibria of Binary Systems Computer Simulation by LabVIEW  A. Belletti, R. Borromei, and G. Ingletto
Reports the results of a program using LabVIEW software to simulate the construction of a phase diagram representing a liquidvapor equilibrium. The program models work in a real laboratory, including mistakes commonly made in this context.
Belletti, A.; Borromei, R.; Ingletto, G. J. Chem. Educ. 2008, 85, 879.
Equilibrium |
Thermodynamics |
Student-Centered Learning
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
Determining the Solubility Product of Fe(OH)3: An Equilibrium Study with Environmental Significance  Michelle Meighan, Joseph MacNeil, and Renee Falconer
This study explores the environmental impact of acidic mine drainage by investigating the relationship between pH and the aqueous solubility of heavy metals. Students precipitate Fe(OH)3 from acidic FeCl3 and NaOH and use the concentrations of ferric and hydroxide ionsdetermined through pH and flame spectroscopyto calculate the Ksp of Fe(OH)3.
Meighan, Michelle; MacNeil, Joseph; Falconer, Renee. J. Chem. Educ. 2008, 85, 254.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
Precipitation / Solubility |
Spectroscopy
Connecting Solubility, Equilibrium, and Periodicity in a Green, Inquiry Experiment for the General Chemistry Laboratory  Kristen L. Cacciatore, Jose Amado, Jason J. Evans, and Hannah Sevian
Presents a novel first-year chemistry experiment that asks students to replicate procedures described in sample lab reports that lack essential information. This structure is designed to promote students' experimental design and data analysis skills as well as their understanding of the importance and essential qualities of written and verbal communication between scientists.
Cacciatore, Kristen L.; Amado, Jose; Evans, Jason J.; Sevian, Hannah. J. Chem. Educ. 2008, 85, 251.
Equilibrium |
Green Chemistry |
Periodicity / Periodic Table |
Solutions / Solvents |
Stoichiometry |
Titration / Volumetric Analysis
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
The Use of Limits in an Advanced Placement Chemistry Course  Paul S. Matsumoto, Jonathan Ring, and Jia Li (Lily) Zhu
This article describes the use of limits in topics usually covered in advanced placement or first-year college chemistry. This approach supplements the interpretation of the graph of an equation since it is usually easier to evaluate the limit of a function than to generate its graph.
Matsumoto, Paul S.; Ring, Jonathan; Zhu, Jia Li (Lily). J. Chem. Educ. 2007, 84, 1655.
Acids / Bases |
Equilibrium |
Gases |
Mathematics / Symbolic Mathematics |
Thermodynamics
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
Peer-Developed and Peer-Led Labs in General Chemistry  Lorena Tribe and Kim Kostka
Describes a student-developed and led laboratory curriculum as a model for producing a more student-centered and rich laboratory experience in general chemistry laboratories.
Tribe, Lorena; Kostka, Kim. J. Chem. Educ. 2007, 84, 1031.
Acids / Bases |
Electrochemistry |
Equilibrium |
Kinetics |
Laboratory Management |
Thermodynamics |
Student-Centered Learning
The Physical Meaning of the Mathematical Formalism Present in Limiting Chemical Equations; Or, How Dilute Is Dilute?  C. Contreras-Ortega, N. Bustamante, J. L. Guevara, C. Portillo, and V. Kesternich
Proposes general mathematical formulations to offer students a better understanding of the real scope of scientific expressions dealing with limiting physical conditions, such as those concerning dilute and concentrated solutions and low and high temperatures and pressures.
Contreras-Ortega, C.; Bustamante, N.; Guevara, J. L.; Portillo, C.; Kesternich, V. J. Chem. Educ. 2007, 84, 788.
Aqueous Solution Chemistry |
Equilibrium |
Gases |
Mathematics / Symbolic Mathematics |
Quantitative Analysis |
Solutions / Solvents
Constructing a Graphic Organizer in the Classroom: Introductory Students' Perception of Achievement Using a Decision Map To Solve Aqueous Acid–Base Equilibria Problems  Stephen DeMeo
A decision map is a directional heuristic that helps learners solve problems within a generic framework. The decision map that is presented was created to solve pH problems of varying difficulty that introductory college chemistry students encounter when studying acidbase equilibria.
DeMeo, Stephen. J. Chem. Educ. 2007, 84, 540.
Acids / Bases |
Equilibrium
Flame Emission Spectrometry in General Chemistry Labs: Solubility Product (Ksp) of Potassium Hydrogen Phthalate  Frazier W. Nyasulu, William Cusworth III, David Lindquist, and John Mackin
In this general chemistry laboratory, flame emission spectrometry is used to determine the potassium ion concentration in saturated solutions of potassium hydrogen phthalate. From these data the solubility products, the Gibbs free energies of solution, the standard enthalpy of solution, and the standard entropy of solution are calculated.
Nyasulu, Frazier W.; Cusworth, William, III; Lindquist, David; Mackin, John. J. Chem. Educ. 2007, 84, 456.
Acids / Bases |
Atomic Properties / Structure |
Spectroscopy |
Equilibrium |
Quantitative Analysis |
Thermodynamics |
Titration / Volumetric Analysis |
Solutions / Solvents |
Aqueous Solution Chemistry |
Atomic Spectroscopy
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
Effectiveness of Conceptual Change-Oriented Teaching Strategy To Improve Students' Understanding of Galvanic Cells  Ali Riza Özkaya, Musa Üce, Hakan Sariçayir, and Musa Sahin
This article presents efforts to develop a conceptual change-oriented strategy to teaching galvanic cells in electrochemistry. The objective is to assess the effectiveness of conceptual change-oriented instruction relative to conventional instruction using statistical comparisons.
Özkaya, Ali Riza; Üce, Musa; Sariçayir, Hakan; Sahin, Musa. J. Chem. Educ. 2006, 83, 1719.
Electrochemistry |
Equilibrium |
Oxidation / Reduction |
Undergraduate Research
Teaching Physical Chemistry Experiments with a Computer Simulation by LabVIEW  A. Belletti, R. Borromei, and G. Ingletto
This article reports on a computer simulation developed with the software LabVIEW of the physical chemistry experiment regarding the vapor pressure measurements of a pure liquid as a function of temperature, as well as a system of data collecting that emphasizes the similarities between the virtual and real experiment.
Belletti, A.; Borromei, R.; Ingletto, G. J. Chem. Educ. 2006, 83, 1353.
Equilibrium |
Laboratory Computing / Interfacing |
Liquids |
Thermodynamics |
Gases |
Student-Centered Learning
Equilibrium Constants and Water Activity Revisited  David Keeports
Subtle arguments based upon the use of chemical potentials show that numerical values of solute molar concentrations can be used as good approximate activities in equilibrium calculations for reactions involving dilute solutions.
Keeports, David. J. Chem. Educ. 2006, 83, 1290.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
Water / Water Chemistry |
Alcohols
Equilibrium Constants and Water Activity Revisited  E. J. Behrman
In teaching the effects of structure on acid strength, it is useful to compare, inter alia, water with primary alcohols.
Behrman, E. J. J. Chem. Educ. 2006, 83, 1290.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
Water / Water Chemistry |
Alcohols
Equilibrium Constants and Water Activity Revisited  E. J. Behrman
In teaching the effects of structure on acid strength, it is useful to compare, inter alia, water with primary alcohols.
Behrman, E. J. J. Chem. Educ. 2006, 83, 1290.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
Water / Water Chemistry |
Alcohols
Lecture Templates: Convenient Partial Lecture Delivery System  Elzbieta Cook and Robert L. Cook
Reports on the use of two forms of PowerPoint lecture presentationsa complete version used by the lecturer and a corresponding partial version available in advance to students. Pre-prepared lecture presentations allow for the sharing of lecture materials among teaching faculty and ensure consistency among several lecture sections in team taught courses.
Cook, Elzbieta; Cook, Robert L. J. Chem. Educ. 2006, 83, 1176.
Equilibrium |
Lewis Structures |
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
(Strept)Avidin–Biotin: Two Interrelated Experiments for the Introductory Chemistry Laboratory  David E. Hansen, Dengda Tang, Jon A. Sanborn, and Mark D. Marshall
Describes a two-experiment sequence focusing on the noncovalent complex between the egg white protein avidin (or the similar protein streptavidin, which is expressed by the bacterium Streptomyces avidinii) and the essential cofactor biotin. The equilibrium constant for the binding of HABA to avidin is calculated from the data collected.
Hansen, David E.; Tang, Dengda; Sanborn, Jon A.; Marshall, Mark D. J. Chem. Educ. 2006, 83, 777.
Bioorganic Chemistry |
Computational Chemistry |
Equilibrium |
Titration / Volumetric Analysis
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
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
Computer Simulations of Salt Solubility  Victor M. S. Gil and João C. M. Paiva
Computer Simulations of Salt Solubility provides an animated, visual interpretation of the different solubilities of related salts based on simple entropy changes associated with dissolution: configurational disorder and thermal disorder.
Gil, Victor M. S.; Paiva, João C. M. J. Chem. Educ. 2006, 83, 173.
Thermodynamics |
Equilibrium |
Solutions / Solvents |
Precipitation / Solubility |
Computational Chemistry
A New Java Animation in Peer-Reviewed JCE WebWare  William F. Coleman and Edward W. Fedosky
Just added to JCE WebWare, Computer Simulations of Salt Solubility uses a Java applet and Web browser to present an animated illustration of differences in the solubility of salts due to differences in the entropy of solvation.
Coleman, William F.; Fedosky, Edward W. J. Chem. Educ. 2006, 83, 173.
Computational Chemistry |
Equilibrium |
Thermodynamics |
Solutions / Solvents |
Precipitation / Solubility
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
Using Visible Spectrophotometers and pH Measurements To Study Speciation in a Guided-Inquiry Laboratory   William H. Otto, Cynthia K. Larive, Susan L. Mason, Janet B. Robinson, Joseph A. Heppert, and James D. Ellis
A collective-effort, guided-inquiry laboratory investigation was developed for the second-semester general chemistry laboratory for the purpose of increasing student conceptual understanding of equilibrium and speciation phenomena. This investigation required students to employ the chemical indicator phenol red in phosphate buffer solution, computer interfaced pH probes, and visible spectrophotometers. Through a combination of potentiometric and visible absorption measurements, the students determined the pH conditions that alter equilibrium concentrations of multiple species (colored and transparent) in solution.
Otto, William H.; Larive, Cynthia K.; Mason, Susan L.; Robinson, Janet B.; Heppert, Joseph A.; Ellis, James D. J. Chem. Educ. 2005, 82, 1552.
Acids / Bases |
UV-Vis Spectroscopy |
Equilibrium |
pH |
Water / Water Chemistry |
Dyes / Pigments
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
Equilibrium Constants and Water Activity  David Keeports
General chemistry instructors are faced with a dilemma when introducing the topic of equilibrium constants: These constants are correctly written in terms of activities, yet activity is a complex topic better treated rigorously in a physical chemistry course than superficially in a general chemistry course. Thus, to introduce equilibrium calculations, it is necessary to use approximate forms for equilibrium constants. However, I find that some commonly used textbooks provide incorrect arguments leading to approximate equilibrium constants for aqueous reactions.
Keeports, David. J. Chem. Educ. 2005, 82, 999.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
Water / Water Chemistry
JavaScript Programs To Calculate Thermodynamic Properties Using Cubic Equations of State  
Cubic equations of state are widely used by chemists and chemical engineers to predict the thermodynamic properties of both pure substances and mixtures. In particular, these equations enable predictions concerning the temperature and pressure at which vaporliquid equilibrium occurs. These two educational JavaScript programs perform calculations using cubic equations of state and, equally importantly, explain how the calculations are performed.
J. Chem. Educ. 2005, 82, 960.
Enrichment / Review Materials |
Equilibrium |
Thermodynamics
JavaScript Programs To Calculate Thermodynamic Properties Using Cubic Equations of State  Patrick J. Barrie
In this article, two JavaScript programs are described. The first program gives students the choice of five different cubic equations of state and performs calculations for pure substances. The second program predicts vaporliquid equilibrium for binary mixtures using a choice of three modern equations of state and the van der Waals mixing rules.
Barrie, Patrick J. J. Chem. Educ. 2005, 82, 958.
Enrichment / Review Materials |
Thermodynamics |
Equilibrium
Procedure for Decomposing a Redox Reaction into Half-Reactions  Ilie Fishtik and Ladislav H. Berka
The principle of stoichiometric uniqueness provides a simple algorithm to check whether a simple redox reaction may be uniquely decomposed into half-reactions in a single way. For complex redox reactions the approach permits a complete enumeration of a finite and unique number of ways a redox reaction may be decomposed into half-reactions. Several examples are given.
Fishtik, Ilie; Berka, Ladislav H. J. Chem. Educ. 2005, 82, 553.
Stoichiometry |
Equilibrium |
Electrochemistry |
Oxidation / Reduction |
Reactions |
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
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
Analysis of Natural Buffer Systems and the Impact of Acid Rain. An Environmental Project for First-Year Chemistry Students  David C. Powers, Andrew T. Higgs, Matt L. Obley, Phyllis A. Leber, Kenneth R. Hess, and Claude H. Yoder
The purpose of this project is to investigate the basic principles involved in acidbase buffer systems within the context of an environmental issue. It is designed for use in an introductory chemistry course. The students will learn about acidbase interactions and examine how a buffer system composed of a weak acid and its conjugate base can neutralize large quantities of strong acid while resisting drastic change in the pH of the system. Students will also analyze experimentally the various components of the most commonly occurring natural buffer system.
Powers, David C.; Higgs, Andrew T.; Obley, Matt L.; Leber, Phyllis A.; Hess, Kenneth R.; Yoder, Claude H. J. Chem. Educ. 2005, 82, 274.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium
Playing Card Equilibrium  Frank L. Lambert
From experience, I am hypersensitive to the misconceptions of students and instructors that can be caused when playing cards are used in teaching chemistry. The root of such errors lies in overlooking the non-mobile, non-energetically-interacting nature of pieces of cardboard. Only if they are being shuffled can cards serve as some sort of analogy to molecular behavior in chemistry.
Lambert, Frank L. J. Chem. Educ. 2004, 81, 1569.
Equilibrium |
Statistical Mechanics |
Thermodynamics
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
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 acidbase 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 acidbase 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 chemists 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
Why Do We Teach Equilibrium Calculations?  Stephen J. Hawkes
Is there any substantial value to students in learning these calculations? Is there value enough to warrant inclusion in the one year of introductory chemistry?
Hawkes, Stephen J. J. Chem. Educ. 2003, 80, 1381.
Equilibrium
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
Applying the Reaction Table Method for Chemical Reaction Problems (Stoichiometry and Equilibrium)  Steven F. Watkins
A systematic approach to chemical reaction calculations (stoichiometry calculations) - the "Reaction Table Method" (similar to the equilibrium table method).
Watkins, Steven F. J. Chem. Educ. 2003, 80, 658.
Equilibrium |
Stoichiometry |
Reactions |
Kinetics
Chemical Equilibria Involving Copper(II) Ethylenediamine Complexes  Roberto Zingales
Demonstration illustrating the formation of two different complexes when copper(II) ions react with ethylenediamine.
Zingales, Roberto. J. Chem. Educ. 2003, 80, 535.
Equilibrium |
Aqueous Solution Chemistry |
Reactions |
Amines / Ammonium Compounds |
Precipitation / Solubility
Chemical Equilibria Involving Reactions of Silver(I) Ions  Roberto Zingales
Demonstrating a series of reactions involving silver(I) ions.
Zingales, Roberto. J. Chem. Educ. 2003, 80, 534.
Equilibrium |
Reactions |
Aqueous Solution Chemistry |
Qualitative Analysis |
Metals |
Precipitation / Solubility
Equilibrium  Matthew Sandberg and Michael K. Bellamy
Software (applet) to help students visualize what actually happens in an equilibrium system.
Sandberg, Matthew ; Bellamy, Michael K. J. Chem. Educ. 2003, 80, 456.
Equilibrium |
Molecular Modeling |
Molecular Mechanics / Dynamics
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
Understanding of Elementary Concepts in Heat and Temperature among College Students and K–12 Teachers  Paul G. Jasien and Graham E. Oberem
Report on a study of the understanding of elementary concepts related to heat and temperature (thermal equilibrium and energy transfer in the form of heat) in undergraduate and post-baccalaurate students as a function of their number of semesters of college-level physical science training.
Jasien, Paul G.; Oberem, Graham E. J. Chem. Educ. 2002, 79, 889.
Thermodynamics |
Equilibrium
Conceptual Difficulties Experienced by Prospective Teachers in Electrochemistry: Half-Cell Potential, Cell Potential, and Chemical and Electrochemical Equilibrium in Galvanic Cells  Ali Riza Özkaya
Study of prospective teachers' conceptual understanding of topics in electrochemistry.
Özkaya, Ali Riza. J. Chem. Educ. 2002, 79, 735.
Electrochemistry |
Equilibrium |
Electrolytic / Galvanic Cells / Potentials
Using Limiting-Excess Stoichiometry to Introduce Equilibrium Calculations: A Discrepant Event Laboratory Activity Involving Precipitation Reactions  Stephen DeMeo
Students are introduced to the concept of equilibrium as they investigate two precipitation reactions, predict which reactant is present in excess, and find that there are two excess reactants.
DeMeo, Stephen. J. Chem. Educ. 2002, 79, 474.
Equilibrium |
Stoichiometry |
Precipitation / Solubility |
Qualitative Analysis
Tick Tock, a Vitamin C Clock  Stephen W. Wright
Uses supermarket chemicals to perform a clock reaction; students vary the concentration of reactants and observe the effect on the time required for the reaction to reach its endpoint.
Wright, Stephen W. J. Chem. Educ. 2002, 79, 40A.
Consumer Chemistry |
Oxidation / Reduction |
Vitamins |
Equilibrium |
Mechanisms of Reactions
Using the Science Writing Heuristic to Move toward an Inquiry-Based Laboratory Curriculum: An Example from Physical Equilibrium  James A. Rudd II, Thomas J. Greenbowe, Brian M. Hand, and Margaret J. Legg
Changing the laboratory report format to improve student understanding of physical equilibrium in the lecture setting using the Science Writing Heuristic.
Rudd, James A., II; Greenbowe, Thomas J.; Hand, Brian M.; Legg, Margaret J. J. Chem. Educ. 2001, 78, 1680.
Equilibrium
Relating Qualitative Analysis to Equilibrium Principles  Glenn V. Lo
Mathcad document intended for a prelab activity for qualitative analysis experiments.
Lo, Glenn V. J. Chem. Educ. 2001, 78, 1557.
Qualitative Analysis |
Equilibrium |
Mathematics / Symbolic Mathematics |
Precipitation / Solubility
The Relative Acidities of Water and Methanol  Henry I. Abrash
Analysis of the disparity between the way the acidity constant of water is presented in general chemistry and organic chemistry textbooks.
Abrash, Henry I. J. Chem. Educ. 2001, 78, 1496.
Acids / Bases |
Equilibrium
Teaching Brønsted-Lowry Acid-Base Theory in a Direct Comprehensive Way  Jamie L. Adcock
Unifying all the Bronsted-Lowry acid-base concepts in a quantitative way.
Adcock, Jamie L. J. Chem. Educ. 2001, 78, 1495.
Acids / Bases |
Equilibrium |
Learning Theories |
Water / Water Chemistry |
Brønsted-Lowry Acids / Bases
Blood-Chemistry Tutorials: Teaching Biological Applications of General Chemistry Material  Rachel E. Casiday, Dewey Holten, Richard Krathen, and Regina F. Frey
Four, Web-based tutorials that deal with chemical processes in the blood and provide an integrated biological context for a variety of chemical concepts.
Casiday, Rachel E.; Holten, Dewey; Krathen, Richard; Frey, Regina F. J. Chem. Educ. 2001, 78, 1210.
Applications of Chemistry |
Medicinal Chemistry |
Proteins / Peptides |
Acids / Bases |
Equilibrium |
Molecular Properties / Structure
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
Are Fizzing Drinks Boiling? A Chemical Insight from Chemical Education Research  Alan Goodwin
The suggestion that fizzing drinks are examples of liquids boiling at room temperature has proved to be controversial among both chemists and chemical educators. This paper presents a case for believing this everyday system to be a good example of a boiling solution and the consequent separation of carbon dioxide from the solution to exemplify fractional distillation.
Goodwin, Alan. J. Chem. Educ. 2001, 78, 385.
Aqueous Solution Chemistry |
Kinetic-Molecular Theory |
Equilibrium |
Gases |
Solutions / Solvents |
Phases / Phase Transitions / Diagrams
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
From Chicken Breath to the Killers Lake of Cameroon: Uniting Seven Interesting Phenomena with a Single Chemical Underpinning  Ron DeLorenzo
By using a single equation prototype, seven interesting mysteries and phenomena can be seen as sharing a common chemical underpinning. The applications discussed are the Killer Lakes of Cameroon, chicken breath, the Permian Ocean, the snow line, boiler scale, the Fizz Keeper, and stalactites and stalagmites.
DeLorenzo, Ronald. J. Chem. Educ. 2001, 78, 191.
Descriptive Chemistry |
Applications of Chemistry |
Equilibrium
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
SolEq: Solution Equilibria, Principles and Applications, Release 1
by SolEq Project Team: L. D. Pettit, K. J. Powell, and R. W. Ramette

  Marina C. Koether
29 tutorials with simulation, calculations, and graphs, on solution equilibria.
Koether, Marina C. J. Chem. Educ. 2000, 77, 1414.
Equilibrium |
Solutions / Solvents |
Titration / Volumetric Analysis

Equilibrium: A Teaching/Learning Activity: Author Reply  Audrey Wilson
Thanks for input.
Wilson, Audrey . J. Chem. Educ. 2000, 77, 1410.
Equilibrium
Equilibrium: A Teaching/Learning Activity  Todd P. Silverstein
Further refinement of equilibrium activity.
Silverstein, Todd P. J. Chem. Educ. 2000, 77, 1410.
Equilibrium
Are We Taking Symbolic Language for Granted?   Paul Marais and Faan Jordaan
This study formed part of a broader investigation into the role of language in teaching and learning chemical equilibrium. Students were tested for their understanding of 25 words and five symbols commonly used in connection with chemical equilibrium. This test showed that most of the students had an inadequate grasp of the meaning of all five symbols. It also showed that, on the average, their understanding of symbols was more problematic than their understanding of words.
Marais, Paul; Jordaan, Faan. J. Chem. Educ. 2000, 77, 1355.
Equilibrium |
Nomenclature / Units / Symbols
Graphing Calculator Strategies for Solving Chemical Equilibrium Problems (re J. Chem. Educ. 1999, 76, 632-634) Author Reply  Henry Donato Jr.
Reinforces appropriateness of application of graphing calculator for solving chemical equilibrium problems.
Donato, Henry, Jr. J. Chem. Educ. 2000, 77, 1120.
Aqueous Solution Chemistry |
Equilibrium
Graphing Calculator Strategies for Solving Chemical Equilibrium Problems (re J. Chem. Educ. 1999, 76, 632-634)  Todd P. Silverstein
Questions appropriateness of application of graphing calculator for solving chemical equilibrium problems.
Silverstein, Todd P. J. Chem. Educ. 2000, 77, 1120.
Aqueous Solution Chemistry |
Equilibrium
Every Year Begins a Millennium  Jerry A. Bell
This article outlines a series of demonstrations and their contexts, leading to recommendations about what we teach and how we teach.
Bell, Jerry A. J. Chem. Educ. 2000, 77, 1098.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
Kinetics |
Learning Theories
Determination of Ksp, ΔG0, ΔH0, and ΔS0 for the Dissolution of Calcium Hydroxide in Water: A General Chemistry Experiment  William B. Euler, Louis J. Kirschenbaum, and Ben Ruekberg
This exercise utilizes low-cost, relatively nonhazardous materials presenting few disposal problems. It reinforces the students' understanding of the interrelationship of solubility, Ksp, ΔG0, ΔH0, and ΔS0.
Euler, William B.; Kirschenbaum, Louis J.; Ruekberg, Ben. J. Chem. Educ. 2000, 77, 1039.
Equilibrium |
Thermodynamics |
Titration / Volumetric Analysis
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
A Closer Look at Phase Diagrams for the General Chemistry Course  Stephen A. Gramsch
The information provided by the high-pressure phase diagrams of some simple systems (carbon dioxide, water, hydrogen, and iron) can provide a useful extension to the traditional discussion of phase diagrams in the general chemistry course. At the same time, it can prepare students for a more illuminating presentation of the concept of equilibrium than is possible through the discussion of gas phase, acid-base, and solubility product equilibria alone.
Gramsch, Stephen A. J. Chem. Educ. 2000, 77, 718.
Equilibrium |
Phases / Phase Transitions / Diagrams |
Thermodynamics |
Geochemistry
Modeling Chemical Processes in Seawater Aquaria to Illustrate Concepts in Undergraduate Chemistry  Gordan Grguric
This paper describes three exercises which can be used in a variety of undergraduate chemistry curricula: (i) determining the salts and their amounts needed to prepare a given volume of artificial seawater, (ii) modeling aqueous carbonate equilibria, to calculate pH and alkalinity shifts through additions of chemicals, and (iii) modeling chemical kinetics involved in aqueous ozone-bromine reactions, to predict the type and extent of disinfection by-products.
Grguric, Gordan. J. Chem. Educ. 2000, 77, 495.
Aqueous Solution Chemistry |
Equilibrium |
Kinetics |
Applications of Chemistry
LeChâtelier's Principle in the Sciences  Volker B. E. Thomsen
The concept of homeostasis in biology and the economic law of supply and demand are both equilibrium-like principles, but involve systems in the steady state. However, all these principles involve the stability of the system under consideration and the analogies presented may be useful in the teaching of LeChtelier's principle.
Thomsen, Volker B. E. J. Chem. Educ. 2000, 77, 173.
Equilibrium |
Learning Theories
An Acid-Base Chemistry Example: Conversion of Nicotine  John H. Summerfield
The current government interest in nicotine conversion by cigarette companies provides an example of acid-base chemistry that can be explained to students in the second semester of general chemistry.
Summerfield, John H. J. Chem. Educ. 1999, 76, 1397.
Acids / Bases |
Drugs / Pharmaceuticals |
Equilibrium
Predicting Acid-Base Titration Curves without Calculations  Dennis W. Barnum
In this paper a qualitative and systematic method for sketching titration curves is presented. Even the more complex cases such as salts or polyprotic acids and bases are treated just as easily as simple monoprotic acids. Having students predict the shape of titration curves from known equilibrium constants helps to focus attention on the general principles without distraction by the mathematics.
Barnum, Dennis W. J. Chem. Educ. 1999, 76, 938.
Acids / Bases |
Quantitative Analysis |
Water / Water Chemistry |
Equilibrium |
Learning Theories |
Titration / Volumetric Analysis |
Chemometrics
Do pH in Your Head  Addison Ault
Every aqueous solution has a pH. Two factors determine this pH: the acidic or basic strength of the solute, and its concentration. When you use pKa values to express acidic and basic strength you can easily estimate the approximate pH of many aqueous solutions of acids, bases, and their salts and their buffers.
Ault, Addison. J. Chem. Educ. 1999, 76, 936.
Equilibrium |
Acids / Bases |
Aqueous Solution Chemistry |
Learning Theories |
Chemometrics |
Brønsted-Lowry Acids / Bases
Equilibrium: A Teaching/Learning Activity (author's reply)  Wilson, Audrey
Thanks for clarification and suggestions.
Wilson, Audrey J. Chem. Educ. 1999, 76, 900.
Equilibrium |
Rate Law
Equilibrium: A Teaching/Learning Activity  Sadavoy, Lyle; Paiva, Joao C. M.; Gil, Victor M. S.
Clarification and suggestions for improvement.
Sadavoy, Lyle; Paiva, Joao C. M.; Gil, Victor M. S. J. Chem. Educ. 1999, 76, 900.
Equilibrium |
Rate Law
The Arrhenius Equation Revisited (author's reply)  Carroll, Harvey F.
Misleading remarks regarding the Arrhenius equation in some general chemistry texts.
Carroll, Harvey F. J. Chem. Educ. 1999, 76, 899.
Equilibrium |
Rate Law
The Arrhenius Equation Revisited  Logan, S. R.
Addition citation on the implications of the Arrhenius equation.
Logan, S. R. J. Chem. Educ. 1999, 76, 899.
Equilibrium |
Rate Law
Why Not Replace pH and pOH by Just One Real Acidity Grade, AG?  Henk van Lubeck
The disadvantages of pH and pOH disappear after replacing them with AG, the acidity grade: AG = log [H+]/[OH-]. AG of neutral solutions equals 0 at all temperatures, whereas AG of acidic solutions is positive and of alkaline solutions, negative. AG offers some other minor advantages as well.
van Lubeck, Henk. J. Chem. Educ. 1999, 76, 892.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium
Discovering a Change in Equilibrium Constant with Change in Ionic Strength: An Empirical Laboratory Experiment for General Chemistry  Richard J. Stolzberg
Spectrophotometric measurements of absorbance of a solution of Fe3+(aq) and SCN-(aq) treated with different amounts of KNO3 are made to determine Kc for the formation of FeSCN2+(aq). Students observe a regular decrease in the value of Kc as the concentration of added KNO3 is increased.
Stolzberg, Richard J. J. Chem. Educ. 1999, 76, 640.
Equilibrium |
Aqueous Solution Chemistry
Graphing Calculator Strategies for Solving Chemical Equilibrium Problems  Henry Donato Jr.
A general method for finding the roots of polynomial equations using the ubiquitous and inexpensive graphing calculator is presented. It is suggested that important reactions, which are not discussed in introductory chemistry courses because of computational considerations, may now be discussed.
Donato, Henry, Jr. J. Chem. Educ. 1999, 76, 632.
Aqueous Solution Chemistry |
Learning Theories |
Equilibrium
Introducing Dynamic Equilibrium as an Explanatory Model  Jan H. Van Driel, Wobbe de Vos, and Nico Verloop
This article describes an educational design for the introduction of chemical equilibrium, in which students' authentic experiences with chemical phenomena play a central role. The students' most effective type of reasoning appeared to be based on the idea that, in a state of equilibrium, all conditions for both the forward and the backward reaction to take place are satisfied.
Van Driel, Jan H.; de Vos, Wobbe; Verloop, Nico. J. Chem. Educ. 1999, 76, 559.
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
Equilibrium Principles: A Game for Students  Lionel J. Edmonson Jr. and Don L. Lewis
The laboratory exercise is a game using marked sugar cubes as dice. The game emphasizes the dynamic character of equilibrium. Forward and reverse rate-constant values are used to calculate an equilibrium constant and to predict equilibrium populations. Predicted equilibrium populations are compared with experimental results.
Edmonson, Lionel J., Jr.; Lewis, Don L. J. Chem. Educ. 1999, 76, 502.
Equilibrium |
Kinetics
A Simplified Method for Finding the pKa of an Acid-Base Indicator by Spectrophotometry  George S. Patterson
Experiments on determining the pKa of an acid-base indicator by visible spectroscopy are often found in analytical and physical chemistry lab texts. The procedure described here is a modification suitable for general chemistry lab students.
Patterson, George S. J. Chem. Educ. 1999, 76, 395.
Acids / Bases |
Equilibrium |
UV-Vis Spectroscopy
The Fizz Keeper, a Case Study in Chemical Education, Equilibrium, and Kinetics  Reed Howald
The chemistry of the loss of carbonation from carbonated beverages on storage is considered. Increasing the pressure of CO2(g) will restore carbonation, but an increase in pressure adding air should not affect the equilibria. It can and does, however, affect the kinetics-the rate at which a new equilibrium is established. Thus the Fizz Keeper is effective for storage of resealed pop containers for hours, but not for periods of weeks or months.
Howald, Reed. J. Chem. Educ. 1999, 76, 208.
Transport Properties |
Equilibrium |
Gases |
Kinetics |
Aqueous Solution Chemistry |
Consumer Chemistry |
Applications of Chemistry
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
The Effects of Salts and Nonelectrolytes on the Solubility of Potassium Bitartrate: An Introductory Chemistry Discovery Experiment  Charles J. Marzzacco
An introductory chemistry discovery experiment on the effect of the presence of various solutes on the solubility of potassium bitartrate (KHT) is presented. Aqueous solutions of KCl, NaCl, MgSO4 and glucose with concentrations ranging from 0.0 to 0.10 M are saturated with KHT. The solubility of the KHT in these various solutions is determined by titration with standardized NaOH solution.
Marzzacco, Charles J. J. Chem. Educ. 1998, 75, 1628.
Solutions / Solvents |
Equilibrium |
Quantitative Analysis
The Ksp-Solubility Conundrum  Roy W. Clark and Judith M. Bonicamp
The authors sought to find those cases of partly soluble substances for which simple calculations such as Ksp=S2, and Ksp=4S3 can realistically be used for computing solubility from Ksp and the reverse calculation. Empirical solubility data are compared with solubilities calculated from reliable Ksp values that have been adjusted for activity coefficients. A table of 18 substances is suggested for textbook use.
Clark, Roy W.; Bonicamp, Judith M. J. Chem. Educ. 1998, 75, 1182.
Equilibrium |
Aqueous Solution Chemistry |
Precipitation / Solubility
What Should We Teach Beginners about Solubility and Solubility Products?  Stephen J. Hawkes
Solubility equilibria are best taught qualitatively in introductory chemistry, leaving the calculations to higher level courses.
Hawkes, Stephen J. J. Chem. Educ. 1998, 75, 1179.
Solutions / Solvents |
Equilibrium |
Precipitation / Solubility
Equilibrium: A Teaching/Learning Activity  Audrey H. Wilson
This article describes hands-on activities for high-school or undergraduate students designed to clarify important concepts involved in early studies of equilibrium. Concepts included are that at equilibrium, rate of forward reaction = rate of backward reaction; concentrations of both reactants and products remain constant; the equilibrium constant is constant at the same temperature but changes as the temperature changes; and equilibrium may be approached from different starting points.
Wilson, Audrey H. J. Chem. Educ. 1998, 75, 1176.
Equilibrium
"Conceptual Questions" on LeChatelier's Principle  Benjamin P. Huddle
Three "conceptual questions" presented are designed to assess the student's ability to conceptualize chemical equilibrium and to predict the effect of changes made to a system at equilibrium, using LeChatelier's principle, without doing any equilibrium constant calculations.
Huddle, Benjamin P. J. Chem. Educ. 1998, 75, 1175.
Equilibrium
Acid-Base Chemistry of the Aluminum Ion in Aqueous Solution  Edward Koubek
A demonstration of the amphoteric behavior of aluminum is given based on an older report that was given many years ago.
Koubek, Edward. J. Chem. Educ. 1998, 75, 60.
Coordination Compounds |
Equilibrium |
Acids / Bases |
Aqueous Solution Chemistry
Acid Rain Demonstration: The Formation of Nitrogen Oxides as a By-Product of High-Temperature Flames in Connection with Internal Combustion Engines  Jerry A. Driscoll
This demonstration illustrates the formation of nitrogen oxides resulting from a high temperature flame.
Driscoll, Jerry A. J. Chem. Educ. 1997, 74, 1424.
Equilibrium |
Learning Theories |
Water / Water Chemistry |
Oxidation / Reduction
Complexometric Titrations: Competition of Complexing Agents in the Determination of Water Hardness with EDTA  M. Cecilia Yappert and Donald B. DuPre
The competition of complexing agents for the same metal ion and the formation of colored metal-ion complexes is demonstrated with the use of an overhead projector. This demonstration can be used to emphasize both the relevance of the relative values of formation constants in the complexation of metal cations and the applicability of complexometric titrations in quantitative chemical analysis.
Yappert, M. Cecilia; DuPre, Donald B. J. Chem. Educ. 1997, 74, 1422.
Equilibrium |
Coordination Compounds |
Qualitative Analysis |
Quantitative Analysis |
Titration / Volumetric Analysis |
Aqueous Solution Chemistry |
Water / Water Chemistry |
Metals
Formation and Dimerization of NO2 A General Chemistry Experiment  April D. Hennis, C. Scott Highberger, and Serge Schreiner*
A general chemistry experiment which illustrates Gay-Lussac's law of combining volumes. Students are able to determine the partial pressures and equilibrium constant for the formation and dimerization of NO2. The experiment readily provides students with data that can be manipulated with a common spreadsheet.
Hennis, April D.; Highberger, C. Scott; Schreiner, Serge. J. Chem. Educ. 1997, 74, 1340.
Gases |
Equilibrium |
Quantitative Analysis |
Stoichiometry
The reply: Ionization Constants  S. Roo, L. Vermeire, and C. Gorller-Walrand
Error regarding the first ionization constant of carbonic acid.
Roo, S.; Vermeire, L.; Gorller-Walrand, C. J. Chem. Educ. 1997, 74, 1160.
Equilibrium |
Solutions / Solvents |
Aqueous Solution Chemistry |
Acids / Bases |
Mathematics / Symbolic Mathematics
Ionization Constants  Morris Bader
Error regarding the first ionization constant of carbonic acid.
Bader, Morris. J. Chem. Educ. 1997, 74, 1160.
Equilibrium |
Solutions / Solvents |
Aqueous Solution Chemistry |
Acids / Bases
Why and How To Teach Acid-Base Reactions without Equilibrium  Terry S. Carlton
A stepwise method enables students to predict which acid-base reactions occur when two solutions are mixed. The complexities of equilibrium are avoided by treating reactions as all-or-none and by providing a table of acids in order of strength.
Carlton, Terry S. J. Chem. Educ. 1997, 74, 939.
Learning Theories |
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium
Ionization or Dissociation?  Emeric Schultz
The use of the terms Dissociation and Ionization in the teaching of chemistry is discussed. It is suggested that the term dissociation, and what it suggests in terms of ordinary language, is inappropriate when used in certain contexts. Since an alternate and more physically correct term, specifically ionization, is available for these contexts, it is argued that this term be used consistently in these contexts.
Schultz, Emeric. J. Chem. Educ. 1997, 74, 868.
Equilibrium |
Nomenclature / Units / Symbols
The Coupling of Related Demonstrations to Illustrate Principles in Chemical Kinetics and Equilibrium  Richard A. Pacer
Two very simple lecture demonstrations, both involving the reaction of magnesium with one or more dilute acids, are linked together to illustrate principles in chemical kinetics and equilibrium.
Pacer, Richard A. J. Chem. Educ. 1997, 74, 543.
Learning Theories |
Acids / Bases |
Equilibrium |
Kinetics |
Rate Law |
Reactions
Chemical Equilibrium (the author replies)  Banerjee, Anil
Item 7 deserves a fuller answer than was provided.
Banerjee, Anil J. Chem. Educ. 1996, 73, A262.
Equilibrium |
Thermodynamics
Chemical Equilibrium  Logan, S. R.
Item 7 deserves a fuller answer than was provided.
Logan, S. R. J. Chem. Educ. 1996, 73, A261.
Equilibrium |
Thermodynamics
Thermodynamics and Spontaneity  Raymond S. Ochs
Despite the importance of thermodynamics as the foundation of chemistry, most students emerge from introductory courses with only a dim understanding of this subject.
Ochs, Raymond S. J. Chem. Educ. 1996, 73, 952.
Thermodynamics |
Learning Theories |
Equilibrium
A Simple Experiment for Demostration of Phase Diagram of Carbon Dioxide   Van T. Lieu
The experiment involves the compression of small pieces of dry ice and carbon dioxide gas mixture in a 1-mL tuberculin syringe with the needle end of the syringe sealed.
J. Chem. Educ. 1996, 73, 837.
Equilibrium |
Phases / Phase Transitions / Diagrams
A Multistep Equilibria-Redox-Complexation Demonstration to Illustrate Le Châtelier's Principle  Tomás G. Berger and Edward K. Mellon
This brief article describes a demonstration that has been used to discuss Le Chtelier's principle, redox chemistry, equilibria versus steady state situations, and solubility of species.
Berger, Tomás G.; Mellon, Edward K. . J. Chem. Educ. 1996, 73, 783.
Oxidation / Reduction |
Equilibrium |
Precipitation / Solubility
SIRS: Simulations and Interactive Resources, III  Martin, John S.
Simulations and Interactive Resources (SIRs) are designed to support interactive lectures in introductory chemistry. This third issue of SIRs includes five new SIRs as well as updated and final versions of all previously published SIRs.
Martin, John S. J. Chem. Educ. 1996, 73, 722.
Periodicity / Periodic Table |
Equilibrium |
Gases |
Thermodynamics |
Reactions |
Electrochemistry |
Kinetics
Visible Ion Exchange Demonstration for Large or Small Lecture Halls  Jerry A. Driscoll
This article presents a very simple experiment involving the sense of smell that students can accomplish during lecture. This classroom exercise involves very little preparation time and can be used to illustrate the important concepts of equilibrium along with acid/base properties of various ions.
Driscoll, Jerry A. J. Chem. Educ. 1996, 73, 639.
Acids / Bases |
Equilibrium
An Approach to Reaction Thermodynamics through Enthalpies, Entropies, and Free Energies of Atomization  James N. Spencer, Richard S. Moog, and Ronald J. Gillespie
An alternative to the conventional method of calculating enthalpies of reaction is presented, using enthalpies of atomization in place of enthalpies of formation. This allows the student to see directly that the reaction enthalpies are determined by the difference in bond strengths in the reactants and products.
James N. Spencer, Richard S. Moog, and Ronald J. Gillespie. J. Chem. Educ. 1996, 73, 631.
Calorimetry / Thermochemistry |
Thermodynamics |
Equilibrium |
Reactions |
Atomic Properties / Structure |
Stoichiometry
Reduction of Viologen Bisphosphonate Dihalide with Aluminum Foil  Peter Abeta Iyere
An elegant undergraduate experiment similar to the popular "Iodine Clock Reaction" employs the reduction of methyl viologen by hydroxide ion. This demonstration can be used as prelaboratory discussion for an undergraduate kinetic experiment based on the same phenomenon.
Iyere, Peter Abeta. J. Chem. Educ. 1996, 73, 455.
Kinetics |
Equilibrium
Solubility and Thermodynamics: An Introductory Experiment  Robert G. Silberman
This article describes a laboratory experiment suitable for high school or freshman chemistry students in which the solubility of potassium nitrate is determined at several different temperatures.
Silberman, Robert G. J. Chem. Educ. 1996, 73, 426.
Precipitation / Solubility |
Thermodynamics |
Equilibrium
Using Quality Circles in General Chemistry  Kogut, Leonard S.
A second semester class in General Chemistry used a student Quality Circle to suggest methods to improve instruction in chemical equilibrium in solution.
Kogut, Leonard S. J. Chem. Educ. 1996, 73, 146.
Equilibrium |
Solutions / Solvents
Preparing "Chameleon Balls" from Natural Plants: Simple Handmade pH Indicator and Teaching Material for Chemical Equilibrium  Naoki Kanda, Takayuki Asano, Toshiyuki Itoh, and Makoto Onoda
Description of preparation and use of polysaccharide beads containing anthocyanins to teach students about chemical equilibrium under different pH conditions.
Kanda, Naoki; Asano, Takayuki; Itoh, Toshiyuki; Onoda, Makota. J. Chem. Educ. 1995, 72, 1131.
Acids / Bases |
Plant Chemistry |
Equilibrium |
Dyes / Pigments |
pH
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
REACT: Exploring Practical Thermodynamic and Equilibrium Calculations  Ramette, Richard W.
Description of REACT software to balance complicated equations; determine thermodynamic data for all reactants and products; calculate changes in free energy, enthalpy, and entropy for a reaction; and find equilibrium conditions for the a reaction.
Ramette, Richard W. J. Chem. Educ. 1995, 72, 240.
Stoichiometry |
Equilibrium |
Thermodynamics |
Chemometrics
A Student's Travels, Close Dancing, Bathtubs, and the Shopping Mall: More Analogies in Teaching Introductory Chemistry   Rayner-Canham, Geoff
Four analogies are described for use in introductory chemistry classes.
Rayner-Canham, Geoff J. Chem. Educ. 1994, 71, 943.
Atomic Properties / Structure |
Molecular Properties / Structure |
Equilibrium
Chemical Equilibrium in the General Chemistry Course  Fainzilberg, Vladimir E.; Karp, Stewart
The first chapters on chemical equilibrium in first-year college chemistry texts make an "error" in the solution of certain types of equilibria problems.
Fainzilberg, Vladimir E.; Karp, Stewart J. Chem. Educ. 1994, 71, 769.
Equilibrium |
Kinetics
Teaching the Truth about pH  Hawkes, Stephen J.
-log[H+] is only an approximation to pH; how to teach pH to avoid misleading students.
Hawkes, Stephen J. J. Chem. Educ. 1994, 71, 747.
pH |
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium
Fruit Anthocyanins: Colorful Sensors of Molecular Milieu  Curtright, Robert D.; Rynearson, James A .; Markwell, John
Provides background and references as a starting point for the further exploration of anthocyanins.
Curtright, Robert D.; Rynearson, James A .; Markwell, John J. Chem. Educ. 1994, 71, 682.
Dyes / Pigments |
Acids / Bases |
Equilibrium |
pH
Computers and Practical Chemistry  Gipps, John
164. Particularly appropriate examples for the computer interfacing of laboratory experiments.
Gipps, John J. Chem. Educ. 1994, 71, 671.
Laboratory Computing / Interfacing |
Acids / Bases |
Equilibrium |
Reactions
Simulations and Interactive Resources  Martin, John S.
12 Simulations and Interactive Resources (SIRs) including Periodic Table Displays, Electron Orbits and Orbitals, Electron Configurations, Barometers and Manometers, Vapor Pressure, Ideal Gas Behavior, Heat Capacity and Heat of Reaction, Approach to Equilibrium, The Law of Chemical Equilibrium, Titration Curves, Electrochemical Cells, and Rate of Reaction.
Martin, John S. J. Chem. Educ. 1994, 71, 667.
Periodicity / Periodic Table |
Atomic Properties / Structure |
Gases |
Calorimetry / Thermochemistry |
Equilibrium |
Titration / Volumetric Analysis |
Electrolytic / Galvanic Cells / Potentials |
Rate Law
Experiments for Modern Introductory Chemistry: Intermolecular Forces and Raoult's Law  Berka, Ladislav H.; Kildahl, Nicholas
Procedure that illustrates the liquid-vapor phase equilibrium of ideal and nonideal solutions.
Berka, Ladislav H.; Kildahl, Nicholas J. Chem. Educ. 1994, 71, 613.
Noncovalent Interactions |
Gas Chromatography |
Gases |
Liquids |
Equilibrium |
Solutions / Solvents
Equilibrium Vapor Pressures: Comparing Pressures Obtained Using a Classical Method with Those from a Laboratory-Computer Interface  Berka, L. H.; Kildahl, N. K.; Bergin, S. J.; Burns, D. S.
Comparing vapor pressures of nitrogen using a glass syringe with those from a Chempac laboratory / computer interfacing system.
Berka, L. H.; Kildahl, N. K.; Bergin, S. J.; Burns, D. S. J. Chem. Educ. 1994, 71, 441.
Equilibrium |
Gases |
Laboratory Computing / Interfacing
Using the Biological Cell in Teaching Electrochemistry  Merkel, Eva Gankiewicz
How electricity is produced in a simple cell is correlated with how commercial batteries work; this concept can then be related to how living cells send electrical impulses.
Merkel, Eva Gankiewicz J. Chem. Educ. 1994, 71, 240.
Electrochemistry |
Electrolytic / Galvanic Cells / Potentials |
Equilibrium
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
Solving equilibria problems with a graphing calculator: A robust method, free of algebra and calculus   Ruch, David K.; Chasteen, T. G.
The method of successive approximations is frequently introduced in freshman chemistry as a means for solving equilibrium equations. However, this often requires an understanding of calculus that is problematic for introductory chemistry students. An alternative method to solving such equations is to use graphic calculators to solve problems graphically.
Ruch, David K.; Chasteen, T. G. J. Chem. Educ. 1993, 70, A184.
Equilibrium |
Chemometrics
Bean counter's caution   Schwartz, Leslie J.
The article "The "Bean Lab' is useful only for elementary mechanisms.
Schwartz, Leslie J. J. Chem. Educ. 1993, 70, 1042.
Equilibrium |
Mechanisms of Reactions
General treatment of aqueous ionic equilibria using predominance diagrams  Vale, J.; Fernandez-Pereira, C.; Alcalde, M.
This paper illustrates the advantage of a unified instructional treatment based on the similarities o equilibria between acid-base and oxidation-reduction reactions that could be used in a general chemistry course.
Vale, J.; Fernandez-Pereira, C.; Alcalde, M. J. Chem. Educ. 1993, 70, 790.
Acids / Bases |
Equilibrium |
Oxidation / Reduction
Using the electrician's multimeter in the chemistry teaching laboratory: Part 1. Colorimetry and thermometry experiments  Andres, Roberto T.; Sevilla, Fortunato, III
The multimeter could be a very useful instrument for the chemistry laboratory bench. In this paper, the versatility of the multimeter in the chemistry teaching laboratory is demonstrated.
Andres, Roberto T.; Sevilla, Fortunato, III J. Chem. Educ. 1993, 70, 514.
Laboratory Equipment / Apparatus |
Equilibrium |
Stoichiometry |
Kinetics |
Calorimetry / Thermochemistry
Equilibrium calculator  Allendoerfer, Robert
A review of a computer program that can calculate equilibrium concentrations of all of the reagents in an arbitrary chemical reaction with as many as five reactants and products.
Allendoerfer, Robert J. Chem. Educ. 1993, 70, 388.
Equilibrium |
Laboratory Computing / Interfacing
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 CoCl2 Thermosiphon   Brown, Justina L.; Battino, Rubin
A novel way to present the temperature dependence of the equilibrium shift using cobalt complexes.
Brown, Justina L.; Battino, Rubin J. Chem. Educ. 1993, 70, 153.
Equilibrium |
Coordination Compounds
Equilibrium Calculator  Allendoerfer, Robert
The equilibrium calculator can calculate the equilibrium concentrations of all reagents in an arbitrary chemical reaction with as many as five reactants and products.
Allendoerfer, Robert J. Chem. Educ. 1993, 70, 126.
Equilibrium |
Chemometrics
The Effect of Pressure on the Equilibrium of the N2O4-NO2 system, and its Classroom Demonstration  Yang, Zhiming
To demonstrate the effects of pressure on equilibrium, the classic use of N2O4-NO2 should be complimented with a congruent demonstration using Br2 gas.
Yang, Zhiming J. Chem. Educ. 1993, 70, 94.
Equilibrium
Monitoring self-association of a hydrophobic peptide with high performance liquid chromatography: An undergraduate kinetic experiment using the antibiotic gramicidin A  Braco, Lorenzo; Ba, M. Carmen; Abad, Concepcin
The authors propose a kinetic experiment that uses high performance liquid chromatography to determine the rate and equilibrium constants in a very simple manner, and separate the molecular species under study.
Braco, Lorenzo; Ba, M. Carmen; Abad, Concepcin J. Chem. Educ. 1992, 69, A113.
HPLC |
Kinetics |
Proteins / Peptides |
Rate Law |
Equilibrium
On the chemically impossible "other" roots in equilibrium calculations, II  Ludwig, Oliver G.
In a previous paper the author described, using mathematics accessible to students, how an equilibrium calculation leading to a quadratic equation may be shown to have but one "chemical" root. The present work extends this demonstration to some reactions leading to cubic equations.
Ludwig, Oliver G. J. Chem. Educ. 1992, 69, 884.
Chemometrics |
Equilibrium
Simple soda bottle solubility and equilibria  Snyder, Cheryl A.; Snyder, Dudley C.
Using a bottle of selzter water and bromocresol green to demonstrate gas-liquid solubility (carbon dioxide in water).
Snyder, Cheryl A.; Snyder, Dudley C. J. Chem. Educ. 1992, 69, 573.
Solutions / Solvents |
Precipitation / Solubility |
Equilibrium |
Gases |
Liquids |
Aqueous Solution Chemistry |
Water / Water Chemistry
An equilibrium machine.  Sawyer, Douglas J.; Martens, Thomas E.
An equilibrium machine powered by air pressure that demonstrates the concepts of equilibrium, activation energy, and catalysis.
Sawyer, Douglas J.; Martens, Thomas E. J. Chem. Educ. 1992, 69, 551.
Equilibrium |
Catalysis |
Laboratory Equipment / Apparatus
The acid equilibrium constant is unity! (the author replies)  Thompson, Ralph J.
The interpretation of thermodynamic equilibrium constants by Baldwin and Burchill is quite proper and technically correct.
Thompson, Ralph J. J. Chem. Educ. 1992, 69, 515.
Acids / Bases |
Equilibrium |
Aqueous Solution Chemistry
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
Determination of the solubility product of copper(II) tartrate  Thomsen, Marcus W.
The spectrophotometric determination of the solubility product of cupric tartrate is an appropriate experiment for the introductory chemistry course.
Thomsen, Marcus W. J. Chem. Educ. 1992, 69, 328.
Equilibrium |
Aqueous Solution Chemistry |
Spectroscopy
The use of equilibrium notation in listings of standard potentials.  Donkersloot, Maarten C. A.
The difficulty in equilibrium notation of standard electrode potentials is due to the convention that half-reactions must be written as reductions if the given potential is to be called a (standard) electrode potential.
Donkersloot, Maarten C. A. J. Chem. Educ. 1992, 69, 256.
Equilibrium |
Electrochemistry
Standard states for water equilibrium (author response).  Campbell, Mark L.; Waite, Boyd A.
For the purposes of comparison only the unconventionally derived Ka values should be used to compare equilibrium constants for other acids to determine relative acid strengths.
Campbell, Mark L.; Waite, Boyd A. J. Chem. Educ. 1992, 69, 256.
Water / Water Chemistry |
Equilibrium |
Brønsted-Lowry Acids / Bases
Standard states for water equilibrium.  Baldwin, W. George; Burchill, C. Eugene.
The authors consider that Ka and Kb values for Bronsted acids and bases in aqueous solution represent one data set describing the properties of solutes in dilute aqueous solution.
Baldwin, W. George; Burchill, C. Eugene. J. Chem. Educ. 1992, 69, 255.
Water / Water Chemistry |
Equilibrium |
Brønsted-Lowry Acids / Bases
A bulletin board demonstration on humidity   Smith, Kurt; Solomon, Sally
A demonstration of the color changes of cobalt chloride with relative humidity is described in this note.
Smith, Kurt; Solomon, Sally J. Chem. Educ. 1991, 68, 1039.
Atmospheric Chemistry |
Equilibrium
Use of liquid oxygen to support combustion   Sullivan, Dan M.
Production, procedure, and safety of demonstrations involving liquid nitrogen in order to demonstrate: Charles' Law, production and properties of liquid oxygen, effects of concentration on reactions and reaction rates, liquefaction and boiling of oxygen kindling temperature, reactions between substances in two different states of matter, and comparison of partial and complete combustion.
Sullivan, Dan M. J. Chem. Educ. 1991, 68, 1036.
Physical Properties |
Gases |
Reactions |
Equilibrium
The "bean lab": A simple introduction to equilibrium   Dickinson, Paul D.; Erharddt, Walt
The "bean lab" in addition to, or in lieu of an actual equilibrium laboratory experiment helps students attain a more concrete understanding of equilibrium constants.
Dickinson, Paul D.; Erharddt, Walt J. Chem. Educ. 1991, 68, 930.
Equilibrium
Chemical equilibrium: VIII. Precipitates   Gordus, Adon A.
The final article in a series (see previous months this year): This article focuses on ionic precipitates in water and how buffered solutions allow easier calculation of solubilities.
Gordus, Adon A. J. Chem. Educ. 1991, 68, 927.
Acids / Bases |
Equilibrium |
pH |
Precipitation / Solubility |
Aqueous Solution Chemistry |
Water / Water Chemistry
Advanced titration plots using spreadsheet scripting  Currie, James O., Jr.; Whiteley, Richard V., Jr.
131. A spreadsheet aids in student understanding of acid/base titration calculations.
Currie, James O., Jr.; Whiteley, Richard V., Jr. J. Chem. Educ. 1991, 68, 923.
Acids / Bases |
Titration / Volumetric Analysis |
pH |
Laboratory Computing / Interfacing |
Equilibrium
Solving quadratic equations to the correct number of significant figures  Thomas, Rudolf
Presenting an application of the successive approximations method for solving quadratic or higher order expressions.
Thomas, Rudolf J. Chem. Educ. 1991, 68, 409.
Equilibrium |
Chemometrics
Acid and base dissociation constants of water and its associated ions  de Lange, A. M.; Potgieter, J. H.
By applying the Bronsted-Lowry concept of acids and bases, one can derive acid and base dissociation constants for water and its associated ions.
de Lange, A. M.; Potgieter, J. H. J. Chem. Educ. 1991, 68, 304.
Acids / Bases |
Equilibrium |
pH |
Brønsted-Lowry Acids / Bases
Approach to equilibrium: The wasp and beetle model. Statistical insight into how equilibrium is achieved and the stability of an equilibrium state  Chang, Albert; Larsen, Russell D.
124. A computer program provides statistical insight into how equilibrium is achieved and the stability of an equilibrium state.
Chang, Albert; Larsen, Russell D. J. Chem. Educ. 1991, 68, 297.
Equilibrium
Chemical equilibrium: III. A few math tricks   Gordus, Adon A.
The third article in a series on chemical equilibrium that considers a few math "tricks" useful in equilibrium calculations and approximations.
Gordus, Adon A. J. Chem. Educ. 1991, 68, 291.
Acids / Bases |
Equilibrium |
Chemometrics |
Titration / Volumetric Analysis
Chemical equilibrium: II. Deriving an exact equilibrium equation   Gordus, Adon A.
In this article appearing in a series on chemical equilibrium, authors consider how to derive a completely general equation for any chemical mixture.
Gordus, Adon A. J. Chem. Educ. 1991, 68, 215.
Equilibrium |
Chemometrics
A simple first-order consecutive rate reaction: A different method for its solution   Hughes, Elvin, Jr.
Power series methods should be used whenever possible in chemistry courses.
Hughes, Elvin, Jr. J. Chem. Educ. 1991, 68, 180.
Chemometrics |
Equilibrium
A simple first-order consecutive rate reaction: A different method for its solution   Castillo S., Carlos; Micolta S., Germania
A different way to present an equilibrium equation that appeared previously in this Journal.
Castillo S., Carlos; Micolta S., Germania J. Chem. Educ. 1991, 68, 179.
Chemometrics |
Equilibrium
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
Calculating equilibrium concentrations by the continuation method  Cobranchi, Daryl P.; Eyring, Edward M.
The use of the continuation method allows the educator to both present more challenging equilibria to the students and to introduce students to another use for a personal computer.
Cobranchi, Daryl P.; Eyring, Edward M. J. Chem. Educ. 1991, 68, 40.
Equilibrium
Measurements of equilibrium constants of acid-base indicators with a blocktronic colorimeter  Walters, David; Birk, James P.
A computer-interfaced measurement of equilibrium constants of acid-base indicators (methyl orange, methyl red, and phenolphthalein).
Walters, David; Birk, James P. J. Chem. Educ. 1990, 67, A252.
Acids / Bases |
Dyes / Pigments |
Spectroscopy |
Equilibrium |
Laboratory Computing / Interfacing
Numerical solutions for diprotic acid equilibria using spreadsheet iterations  Parker, O. Jerry; Breneman, Gary L.
This software affords the opportunities of solving the problem in an open format that displays any desired intermediate steps as well as final results.
Parker, O. Jerry; Breneman, Gary L. J. Chem. Educ. 1990, 67, A5.
Acids / Bases |
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
Calculation of equilibrium constant in esterification reactions  Sarlo, Edward; Svoronos, Paris; Kulas, Patricia
Procedure for measuring the equilibrium constant in esterification reactions.
Sarlo, Edward; Svoronos, Paris; Kulas, Patricia J. Chem. Educ. 1990, 67, 796.
Esters |
Alcohols |
Carboxylic Acids |
Equilibrium
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
A modified graphical method for acid-base equilibria  Nakagawa, Kuniaki
A method based on logarithmic diagrams for finding the pH values for various systems in acid-base equilibria.
Nakagawa, Kuniaki J. Chem. Educ. 1990, 67, 673.
Acids / Bases |
Equilibrium |
pH
A visual demonstration of Raoult's law  Wilson, Archie S.
Reducing the vapor pressure of bromine by adding chloroform.
Wilson, Archie S. J. Chem. Educ. 1990, 67, 598.
Gases |
Equilibrium
Another look at a mechanical model of chemical equilibrium  Laurita, William
Colored water is transferred back and forth through glass tubing between two graduated cylinders.
Laurita, William J. Chem. Educ. 1990, 67, 598.
Equilibrium
Solving quadratic equations  Brown, R. J. C.
A better technique than the quadratic equation for chemical equilibria is offered here.
Brown, R. J. C. J. Chem. Educ. 1990, 67, 409.
Chemometrics |
Equilibrium
A small scale equilibrium experiment   Flash, Patrick
An alternative method for the experiment in which the equilibrium constant for the iron-thiocyanate complex is determined.
Flash, Patrick J. Chem. Educ. 1990, 67, 341.
Equilibrium |
Reactions
Solution of acid-base equilibria by successive approximations  Olivieri, Alejandro C.
The use of the method of successive approximations for solving acid-base equilibria, in conjunction with an intuitive, chemically based analysis is presented.
Olivieri, Alejandro C. J. Chem. Educ. 1990, 67, 229.
Acids / Bases |
Equilibrium
An efficient method for the treatment of weak acid/base equilibria  Burness, James H.
The use of the ionization ratio concept enables students to perform many of the calculations for aqueous acid/base equilibria more quickly and efficiently.
Burness, James H. J. Chem. Educ. 1990, 67, 224.
Equilibrium |
Acids / Bases
The extent of acid-base reactions  Thompson, Ralph J.
How to calculate the equilibrium constant of an acid-base reaction.
Thompson, Ralph J. J. Chem. Educ. 1990, 67, 220.
Acids / Bases |
Reactions |
Equilibrium
Solving equilibrium constant expressions using spreadsheets  Metz, Clyde; Donato, Henry, Jr.
Description and application of solving equilibrium constant expressions using spreadsheets.
Metz, Clyde; Donato, Henry, Jr. J. Chem. Educ. 1989, 66, A241.
Equilibrium
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
Overall chemical equations  Gil, Victor M. S.
An equation sum can be used safely by itself in stoichiometric and equilibrium calculations only if the intermediates produced in separate reactions are at low steady-state concentrations and if there are no other equilibria involving those species.
Gil, Victor M. S. J. Chem. Educ. 1989, 66, 324.
Stoichiometry |
Equilibrium
A simple explanation of the salt water oscillator  Noyes, Richard M.
Yoshikawa et al. have described a simple device that undergoes repeated oscillations and that can also illustrate some of the principles essential to the oscillators driven by chemical reactions.
Noyes, Richard M. J. Chem. Educ. 1989, 66, 207.
Laboratory Equipment / Apparatus |
Thermodynamics |
Equilibrium
Amusement with a salt-water oscillator  Yoshikawa, Kenichi; Nakata, Satoshi; Yamanaka, Masahiro; Waki, Takeshi
Rhythmic oscillations of water flow are generated when a vertically oriented hypodermic syringe, with the plunger removed, is filled with salt water and partially submerged in a beaker of pure water.
Yoshikawa, Kenichi; Nakata, Satoshi; Yamanaka, Masahiro; Waki, Takeshi J. Chem. Educ. 1989, 66, 205.
Thermodynamics |
Equilibrium |
Laboratory Equipment / Apparatus
Chemistry according to ROF (Fee, Richard)  Radcliffe, George; Mackenzie, Norma N.
Two reviews on a software package that consists of 68 programs on 17 disks plus an administrative disk geared toward acquainting students with fundamental chemistry content. For instance, acids and bases, significant figures, electron configuration, chemical structures, bonding, phases, and more.
Radcliffe, George; Mackenzie, Norma N. J. Chem. Educ. 1988, 65, A239.
Chemometrics |
Atomic Properties / Structure |
Equilibrium |
Periodicity / Periodic Table |
Periodicity / Periodic Table |
Stoichiometry |
Physical Properties |
Acids / Bases |
Covalent Bonding
Solution equilibrium problems(Moss, David B.)  Cass, Don; Murray, Marilee
Two reviews of a two disk set with a 44-page manual that discusses equilibria in general and specific techniques of solving equilibrium problems.
Cass, Don; Murray, Marilee J. Chem. Educ. 1988, 65, A114.
Equilibrium
Chemical principles for the introductory laboratory, CHM 384 (Johnson, James F.)  Wegner, Carol
A comprehensive review of the title program which overviews basic techniques and concepts presented in introductory laboratory courses. Topics include: titration, equilibrium, Ksp, solubility, Beer's law, coordination complexes and first-order rates of reaction.
Wegner, Carol J. Chem. Educ. 1988, 65, A47.
Acids / Bases |
Titration / Volumetric Analysis |
UV-Vis Spectroscopy |
Equilibrium |
Solutions / Solvents |
Coordination Compounds |
Kinetics
Oscillating reactions   Kolb, Doris.
A demonstration done on the overhead that oscillates.
Kolb, Doris. J. Chem. Educ. 1988, 65, 1004.
Reactions |
Equilibrium |
Kinetics
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
The perils of carbonic acid and equilibrium constants  Jencks, William P.; Altura, Rachel A.
It is important to remember that the small amounts of carbon dioxide that are usually present in water can have large effects on acid-base equilibria of dilute solutions and that dilute solutions of most weak acids and bases undergo significant protonation or hydrolysis when they are dissolved in water.
Jencks, William P.; Altura, Rachel A. J. Chem. Educ. 1988, 65, 770.
Acids / Bases |
Equilibrium |
Aqueous Solution Chemistry
A "semimicro" spectrophotometric determination of the Ksp of silver acetate at various temperatures  Liebermann, John, Jr.; Yun, Ki J.
An experiment appropriate for Advanced Placement high school chemistry courses.
Liebermann, John, Jr.; Yun, Ki J. J. Chem. Educ. 1988, 65, 728.
Equilibrium |
Spectroscopy
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
Some analogies for teaching rates/equilibrium   Olney, David J.
This article presents several analogies for teaching rates and equilibrium developed by the author over his many years in the chemistry classroom that seem to be effective.
Olney, David J. J. Chem. Educ. 1988, 65, 696.
Kinetics |
Equilibrium
Will that pop bottle really go pop? An equilibrium question  Deamer, David W.; Selinger, Benjamin K.
These authors challenge a claim that appeared in the journal *New Scientist* regarding carbon dioxide in carbonated beverages and equilibrium.
Deamer, David W.; Selinger, Benjamin K. J. Chem. Educ. 1988, 65, 518.
Applications of Chemistry |
Gases |
Equilibrium
A simple, vivid demonstration of selective precipitation   Chirpich, Thomas P.
A simple, vivid demonstration that is designed to catch the students' attention and illustrate the principles of selective, or fractional, precipitation in action.
Chirpich, Thomas P. J. Chem. Educ. 1988, 65, 359.
Equilibrium |
Aqueous Solution Chemistry
An overhead demonstration of some descriptive chemistry of the halogens and LeChtelier's principle  Hansen, Robert C.
Colorful demonstrations that illustrate Le Chtelier's principle, solubility rules, and periodic trends.
Hansen, Robert C. J. Chem. Educ. 1988, 65, 264.
Equilibrium |
Descriptive Chemistry |
Periodicity / Periodic Table
Potentiometric titration of acidic and basic compounds in household cleaners  Lieu, Van T.; Kalbus, Gene E.
The potentiometric titration of commercial household cleaners can be used in student laboratories in freshman, analytical, and physical chemistry courses. It can be used for analysis of household cleaners with either one or two component systems, or it can be used for the determination of the dissociation constant.
Lieu, Van T.; Kalbus, Gene E. J. Chem. Educ. 1988, 65, 184.
Acids / Bases |
Potentiometry |
Consumer Chemistry |
Titration / Volumetric Analysis |
Equilibrium |
Quantitative Analysis
Computer-Assisted Blackboard (Soltzberg, L. J.)  Kruger, J. D.
8-disk set of programs (Apple II) designed to help a lecturer illustrate gas laws, the Rutherford atomic model, quantization in a Bohr atom, wave-functions and orbitals, heat and changes in state, kinetics and simple reaction mechanisms, equilibrium, acid-base reactions, and titrations.
Kruger, J. D. J. Chem. Educ. 1987, 64, A135.
Acids / Bases |
Gases |
Atomic Properties / Structure |
Phases / Phase Transitions / Diagrams |
Kinetics |
Mechanisms of Reactions |
Equilibrium |
Titration / Volumetric Analysis
Correct equilibrium constants for water (the authors reply)  Starkey, Ronald; Norman, Jack; Hinitze, Mark
Water and hydronium ion Ka values are special cases.
Starkey, Ronald; Norman, Jack; Hinitze, Mark J. Chem. Educ. 1987, 64, 1068.
Equilibrium |
Water / Water Chemistry |
Aqueous Solution Chemistry |
Acids / Bases |
Thermodynamics
Correct equilibrium constants for water  Baldwin, W. George; Burchill, C. Eugene
Disagreement with the numerical values assigned to equilibrium constants.
Baldwin, W. George; Burchill, C. Eugene J. Chem. Educ. 1987, 64, 1067.
Equilibrium |
Water / Water Chemistry |
Acids / Bases |
Aqueous Solution Chemistry
Computer programming in general chemistry  Breneman, G. L.; Parker, O. J.
84. Programming computers to solve problems as an integral part of the general chemistry course.
Breneman, G. L.; Parker, O. J. J. Chem. Educ. 1987, 64, 584.
Titration / Volumetric Analysis |
Equilibrium
Thermodynamics of the rhodamine B lactone zwitterion equilibrium: An undergraduate laboratory experiment  Hinckley, Daniel A.; Seybold, Paul G.
An experiment to derive thermodynamic values from a thermochromic equilibrium that uses a commercially available dye, attains equilibrium rapidly, and employs a simple, single-beam spectrophotometer.
Hinckley, Daniel A.; Seybold, Paul G. J. Chem. Educ. 1987, 64, 362.
Thermodynamics |
Dyes / Pigments |
Spectroscopy |
Equilibrium
Introduction to overhead projector demonstrations  Kolb, Doris
General suggestions for using the overhead projector and 21 demonstrations. [Debut]
Kolb, Doris J. Chem. Educ. 1987, 64, 348.
Rate Law |
Reactions |
Catalysis |
Equilibrium |
Transition Elements |
Metals |
Oxidation / Reduction |
Acids / Bases
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
VisiChem  Breneman, G. L.
70. Bits and pieces, 28. Many of the business spreadsheet programs can be used to answer "What if?" questions in chemistry due to the mathematical functions needed for science (such as logs, trig functions, square root) and others.
Breneman, G. L. J. Chem. Educ. 1986, 63, 321.
Noncovalent Interactions |
Equilibrium
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
The solubility of CaSO4 (the author replies)  Sawyer, Albert K.
Reasons why the lab determination of Ksp for CaSO4 is ten times higher than the published value.
Sawyer, Albert K. J. Chem. Educ. 1985, 62, 362.
Precipitation / Solubility |
Equilibrium |
Aqueous Solution Chemistry
The solubility of CaSO4   Hawkes, Stephen J.
Reasons why the lab determination of Ksp for CaSO4 is ten times higher than the published value.
Hawkes, Stephen J. J. Chem. Educ. 1985, 62, 362.
Precipitation / Solubility |
Equilibrium |
Aqueous Solution Chemistry
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
Thermodynamic changes, kinetics, equilibrium, and LeChatelier's principle  Hansen, Robert C.
A series of demonstrations in which water in beakers and the flow of water between beakers is used to represent the components of an exothermic chemical reaction and the flow and quantity of thermal energy involved in chemical changes.
Hansen, Robert C. J. Chem. Educ. 1984, 61, 804.
Equilibrium |
Kinetics |
Thermodynamics
The goals of teaching solution equilibrium  Ruda, Paul T.
Using and making relevant the concepts of solution equilibrium.
Ruda, Paul T. J. Chem. Educ. 1984, 61, 784.
Equilibrium |
Solutions / Solvents
Why teach solution equilibrium?  Butler, James N.
What are the most important aspects of solution equilibrium to teach at the elementary level?
Butler, James N. J. Chem. Educ. 1984, 61, 784.
Equilibrium |
Solutions / Solvents |
Acids / Bases |
pH
The solubility of NiSO46H2O  Pacer, Richard A.
Approaches the position of equilibrium from both unsaturated and supersaturated solutions.
Pacer, Richard A. J. Chem. Educ. 1984, 61, 467.
Aqueous Solution Chemistry |
Solutions / Solvents |
Precipitation / Solubility |
Equilibrium |
UV-Vis Spectroscopy
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
Metal-ligand complexes-a calculation challenge  Ramette, R. W.
The purpose of this paper is to illustrate one of the most important experimental methods for studying complex equilibria and to present synthetic data as a challenge to the many sophisticated calculation procedure that enjoy various degrees of loyalty around the world.
Ramette, R. W. J. Chem. Educ. 1983, 60, 946.
Equilibrium |
Metals |
Electrochemistry |
Oxidation / Reduction |
Coordination Compounds
NH4HC03: a stimulant for learning  Richards, R. Ronald
Students, professors, and the literature have all been confused by the unusual dissociation equilibrium of NH4HCO3.
Richards, R. Ronald J. Chem. Educ. 1983, 60, 555.
Equilibrium |
Amines / Ammonium Compounds |
Gases
On the chemically impossible "other" roots in equilibrium problems  Ludwig, Oliver G.
Students often have a hard time knowing when to disregard equilibrium roots that are too large or are negative. The author suggests a convincing proof that helps students understand how the relationship between the conceptual and mathematical.
Ludwig, Oliver G. J. Chem. Educ. 1983, 60, 547.
Equilibrium |
Chemometrics
Solubility and Ksp of calcium sulfate: a general chemistry laboratory experiment  Sawyer, Albert K.
The experiment shared in this note can be used to accompany lectures on solubility or chemical equilibrium.
Sawyer, Albert K. J. Chem. Educ. 1983, 60, 416.
Solutions / Solvents |
Aqueous Solution Chemistry |
Equilibrium
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
Small things and large numbers   Rosenberg, Milton H.
Some challenging solubility problems are featured in this note.
Rosenberg, Milton H. J. Chem. Educ. 1981, 58, 962.
Solutions / Solvents |
Equilibrium |
Chemometrics
Ksp made simple  Buss, Donald E.
Students often have a hard time understanding solubility products conceptually. The author provides appropriate questions that can better scaffold understanding.
Buss, Donald E. J. Chem. Educ. 1981, 58, 958.
Equilibrium |
Solutions / Solvents
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
Dissociation of a weak acid  Ladd, M. F. C.
An earlier treatment of the equilibrium of a weak acid in water gives, for certain ranges of concentration, significantly incorrect results.
Ladd, M. F. C. J. Chem. Educ. 1980, 57, 669.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
Chemometrics
Cobalt complexes in equilibrium  Ophardt, Charles E.
This equilibrium illustrates the application of LeChatelier's principle to concentration effects.
Ophardt, Charles E. J. Chem. Educ. 1980, 57, 453.
Equilibrium |
Coordination Compounds |
Aqueous Solution Chemistry |
Solutions / Solvents
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
"To sink or swim"  O'Connor, Rod
A problem regarding the maximum water hardness that can be permitted in a swimming pool if it is desired to avoid calcite formation given the carbonate ion concentration. [Debut]
O'Connor, Rod J. Chem. Educ. 1980, 57, 151.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
Solutions / Solvents
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
Strong and weak acids and bases  Deck, Joseph C.
The designations "strong" and "weak" are used in various ways, and often with respect to the same compound in different situations.
Deck, Joseph C. J. Chem. Educ. 1979, 56, 814.
Acids / Bases |
Equilibrium |
Aqueous Solution Chemistry
The gases of life  J. Chem. Educ. Staff
Considers the topics of diffusion, oxygen transport through the lungs, oxygen in arterial blood, and CO2 transfer.
J. Chem. Educ. Staff J. Chem. Educ. 1979, 56, 748.
Gases |
Transport Properties |
Equilibrium
Research and chemistry teaching  Smith, Douglas D.
Student misconceptions about chemical equilibrium.
Smith, Douglas D. J. Chem. Educ. 1979, 56, 609.
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
Chemistry concatenated  Beaumont, R. C.
A series of chemical reactions featuring reversible equilibria and nine major color changes.
Beaumont, R. C. J. Chem. Educ. 1979, 56, 37.
Reactions |
Equilibrium
Determination of the equilibrium constant for triiodide formation. Use of a less toxic solvent  Ackermann, Martin N.
A typical equilibrium laboratory may be hazardous for inexperienced students to perform.
Ackermann, Martin N. J. Chem. Educ. 1978, 55, 795.
Equilibrium
A demonstration of the relationship between rate constants and equilibrium constants   Smoot, Felicia; Ragan, Shirley; Burkett, Alan R.
This demonstration is designed to point out the relationships and distinctions between rate constants, rate expressions, and equilibrium constants.
Smoot, Felicia; Ragan, Shirley; Burkett, Alan R. J. Chem. Educ. 1978, 55, 790.
Equilibrium |
Rate Law
Minimizing the free energy: a computer method for teaching chemical equilibrium concepts  Heald, Emerson F.
This paper presents an alternative method to the standard treatment of equilibrium which uses material balance conditions and the minimization of the free energy. Both concepts are often omitted or glossed over in introductory treatments of equilibrium.
Heald, Emerson F. J. Chem. Educ. 1978, 55, 641.
Equilibrium
Intuitive and general approach to acid-base equilibrium calculations  Felty, Wayne L.
The purpose of this paper is to show that the usual intuitive approach used in general chemistry can be readily extended without introduction of additional, sophisticated concepts to give the general, exact expression and to point out the pedagogical advantage of its use.
Felty, Wayne L. J. Chem. Educ. 1978, 55, 576.
Acids / Bases |
Equilibrium |
Chemometrics
Temperature dependence of Kw   Steffel, M. J.
The question presented in this note requires the resolution of a conflict between a common sense notion and an isolated fact.
Steffel, M. J. J. Chem. Educ. 1978, 55, 243.
Equilibrium
Le Chtelier's principle demonstrated with a rubber band  Smith, Douglas D.
Heating a rubber band causes it to contract and stretching it causes it to become warmer.
Smith, Douglas D. J. Chem. Educ. 1977, 54, 701.
Equilibrium |
Thermodynamics
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
Programmable pocket electronic calculators in the classroom  Weldert, Robert W.
Using programmable calculators in grading and a lab activity involving equilibrium.
Weldert, Robert W. J. Chem. Educ. 1977, 54, 628.
Equilibrium
Ability grouping and a quasi-historical approach  Quiring, Frank S.
Organization of a first-year, high school chemistry course entitled "Quantitative Chemistry," and methods for teaching chemical equilibrium.
Quiring, Frank S. J. Chem. Educ. 1977, 54, 623.
Equilibrium
Simultaneous equilibria involving insoluble salts  Baumann, Jacob B.
This demonstration is derived from and involves the same reactions as the Mohr titration of chloride ion with silver nitrate solution using potassium chromate as an indicator.
Baumann, Jacob B. J. Chem. Educ. 1977, 54, 618.
Equilibrium |
Precipitation / Solubility |
Aqueous Solution Chemistry
Water dipping kinetics. A physical analog for chemical kinetics  Birk, James P.; Gunter, S. Kay
Physical analogs of zero-, first, and second-order kinetics using the volume of water transferred by a dipper oriented in different directions with respect to a basin of water.
Birk, James P.; Gunter, S. Kay J. Chem. Educ. 1977, 54, 557.
Kinetics |
Equilibrium |
Rate Law
An aid to teaching weak acids and bases  Kennedy, David E. B.
A visual aid in helping students understand equilibrium concepts related to weak acids and bases.
Kennedy, David E. B. J. Chem. Educ. 1977, 54, 550.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium
Silver ion in water purification: A follow-up  Quane, Denis
Applying a previous idea on the possible use of silver ion in water purification to teaching the concept of Ksp.
Quane, Denis J. Chem. Educ. 1977, 54, 381.
Aqueous Solution Chemistry |
Water / Water Chemistry |
Equilibrium |
Solutions / Solvents
The effects of HCl and aspirin on the stomach: An equilibrium review  DeLorenzo, Ronald
The chemical effect and medical implications of taking aspirin.
DeLorenzo, Ronald J. Chem. Educ. 1977, 54, 306.
Equilibrium |
Acids / Bases |
pH |
Drugs / Pharmaceuticals |
Medicinal Chemistry |
Applications of Chemistry
Questions [and] Answers  Campbell, J. A.
290-297. Eight questions regarding practical applications of chemistry, primarily in the medical field, and their answers.
Campbell, J. A. J. Chem. Educ. 1977, 54, 247.
Toxicology |
Equilibrium |
Metabolism |
Medicinal Chemistry |
Applications of Chemistry |
Enrichment / Review Materials
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
Effect of Ionic Strength on Equilibrium Constants  Seymour, M. D.; Fernando, Quintus
Involves the determination of the acid dissociation constant of bromcresol green by a spectrophotometric method; using a graphing calculator, each student can perform the laboratory work and obtain his own data set.
Seymour, M. D.; Fernando, Quintus J. Chem. Educ. 1977, 54, 225.
Acids / Bases |
Aqueous Solution Chemistry |
Equilibrium |
pH
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
Chemical equilibrium  Burke, Barbara A.
Demonstrates the equilibrium between blue CuSO4 and green K2(CuBr4) on an overhead projector.
Burke, Barbara A. J. Chem. Educ. 1977, 54, 29.
Equilibrium |
Solutions / Solvents |
Aqueous Solution Chemistry
A Mechanical demonstration of approach to equilibrium  Martin, Dean F.
This demonstration combines audience participation with analogy to demonstrate a principle.
Martin, Dean F. J. Chem. Educ. 1976, 53, 634.
Equilibrium
A criterion for the simple approximation in dissociation equilibria  Leffler, Amos J.
The author demonstrates quantitative criterion for the assumption that permits the neglect of the amount of dissociated species in the denominator of the dissociation equation.
Leffler, Amos J. J. Chem. Educ. 1976, 53, 460.
Acids / Bases |
Equilibrium |
Chemometrics
Equilibrium: A novel classroom demonstration  Hambly, Gordon F.
Demonstrating equilibrium by throwing styrofoam balls back-and-forth between two groups of students.
Hambly, Gordon F. J. Chem. Educ. 1975, 52, 519.
Equilibrium
Equilibrium: A novel classroom demonstration  Hambly, Gordon F.
Demonstrating equilibrium by throwing styrofoam balls back-and-forth between two groups of students.
Hambly, Gordon F. J. Chem. Educ. 1975, 52, 519.
Equilibrium
A computer program to support equilibrium constant theory  Thielmann, Vernon
A Fortran IV program calculates ten different K values based on different equilibrium expressions that are chosen at random.
Thielmann, Vernon J. Chem. Educ. 1975, 52, 468.
Equilibrium
Maximizing profits in equilibrium processes  Rish, Ronald J.
Provides the student with an example in which both chemical principles and calculus are applied to a realistic industrial situation where profits are a must.
Rish, Ronald J. J. Chem. Educ. 1975, 52, 441.
Equilibrium |
Industrial Chemistry |
Chemometrics
Hydrocarbon combustion equilibria in first-year chemistry  Davidson, Scott
An article describing a way to extend the study of multiple equilibria to gaseous systems is available on request.
Davidson, Scott J. Chem. Educ. 1975, 52, 387.
Equilibrium |
Gases
Molar solubility calculations and the control equilibrium  Chaston, S. H. H.
The Control-Equilibrium method uses as its starting point a precise procedure for obtaining the equilibrium that accounts for the bulk of the decomposition of starting materials.
Chaston, S. H. H. J. Chem. Educ. 1975, 52, 206.
Solutions / Solvents |
Chemometrics |
Equilibrium
FeSCN2+ - A computer aid to the CHEM Study experiment  McCall, Arthur J., Jr.
A Fortran program assists in making the calculations that accompany investigation of the iron(III)thiocyanate equilibrium system.
McCall, Arthur J., Jr. J. Chem. Educ. 1975, 52, 118.
Equilibrium |
Aqueous Solution Chemistry |
Chemometrics
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
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
Estimating equilibrium constants  Harrington, Ernest C.
This demonstration allows the class to compare hydrochloric and acetic acid quantitatively and actually determine the ionization constant of acetic acid using a standard classroom conductivity apparatus.
Harrington, Ernest C. J. Chem. Educ. 1973, 50, 549.
Equilibrium |
Acids / Bases
Cooking Succulent Roasts  Plumb, Robert C.; Davis, Adelle
Allowing a roast to gradually warm to the desired internal temperature produces superior results.
Plumb, Robert C.; Davis, Adelle J. Chem. Educ. 1973, 50, 425.
Consumer Chemistry |
Food Science |
Kinetics |
Equilibrium |
Rate Law |
Applications of Chemistry
Cooking Succulent Roasts  Plumb, Robert C.; Davis, Adelle
Allowing a roast to gradually warm to the desired internal temperature produces superior results.
Plumb, Robert C.; Davis, Adelle J. Chem. Educ. 1973, 50, 425.
Consumer Chemistry |
Food Science |
Kinetics |
Equilibrium |
Rate Law |
Applications of Chemistry
The equilibrium between a solid solution and an aqueous solution of its ions  Berndt, Alan F.; Stearns, Robert I.
It is the purpose of this paper to present the equations that describe the equilibrium between solid solutions and their ions and to outline methods for their derivation.
Berndt, Alan F.; Stearns, Robert I. J. Chem. Educ. 1973, 50, 415.
Equilibrium |
Solutions / Solvents |
Aqueous Solution Chemistry
Physical chemistry of the drinking duck  Plumb, Robert C.; Wagner, Robert E.
The operation of the drinking bird is easily understood in terms of a few elementary physical chemistry principles.
Plumb, Robert C.; Wagner, Robert E. J. Chem. Educ. 1973, 50, 213.
Thermodynamics |
Phases / Phase Transitions / Diagrams |
Equilibrium
Auto windows - Strong but self-destructing  Stookey, S. D.
Auto windowglass illustrates the principles of metastable equilibrium.
Stookey, S. D. J. Chem. Educ. 1973, 50, 131.
Applications of Chemistry |
Solids |
Equilibrium
LeChatelier's principle and a rubber band  DeLorenzo, Ronald
The cited demonstration can also be sued to illustrate LeChatelier's principle .
DeLorenzo, Ronald J. Chem. Educ. 1973, 50, 124.
Equilibrium |
Thermodynamics
Chemical Equilibrium: An Introduction (Coe, J.S.)  Hoffman, William A.

Hoffman, William A. J. Chem. Educ. 1972, 49, A311.
Equilibrium
Passage of fruit flies through a hole. A model for a reversible chemical reaction  Runquist, Elizabeth A.; Runquist, Olaf
The passage of fruit flies through a single orifice provides an excellent model for illustrating the principles of equilibrium and chemical dynamics; the results are found to be temperature dependent and reproducible.
Runquist, Elizabeth A.; Runquist, Olaf J. Chem. Educ. 1972, 49, 534.
Reactions |
Equilibrium |
Kinetics |
Rate Law
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
Squeak, skid and glide - The unusual properties of snow and ice  Plumb, Robert C.; Fletcher, N. H.
The Clapeyron equation controls the behavior of ice under varying conditions of temperature and pressure.
Plumb, Robert C.; Fletcher, N. H. J. Chem. Educ. 1972, 49, 179.
Water / Water Chemistry |
Phases / Phase Transitions / Diagrams |
Equilibrium
Squeak, skid and glide - The unusual properties of snow and ice  Plumb, Robert C.; Fletcher, N. H.
The Clapeyron equation controls the behavior of ice under varying conditions of temperature and pressure.
Plumb, Robert C.; Fletcher, N. H. J. Chem. Educ. 1972, 49, 179.
Water / Water Chemistry |
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
A unified introductory chemistry laboratory  Splittgerber, A. G.; MacLean, D. B.; Neils, J.
Common criticisms against chemistry learning laboratories accuse typical first year laboratories of painting an inaccurate portrait of the nature of the chemistry research experience. The author propose a project-type unified laboratory program.
Splittgerber, A. G.; MacLean, D. B.; Neils, J. J. Chem. Educ. 1971, 48, 330.
Undergraduate Research |
Synthesis |
Separation Science |
Equilibrium |
Qualitative Analysis
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
Miscellaneous  Alyea, Hubert N.
These twelve overhead projection demonstrations include rates of reactions, clock reactions, the effect of temperature and the presence of a catalyst on the decomposition of hydrogen peroxide, the relationship between viscosity and temperature, equilibria, solubility product, and the common ion effect.
Alyea, Hubert N. J. Chem. Educ. 1970, 47, A437.
Oxidation / Reduction |
Kinetics |
Rate Law |
Reactions |
Acids / Bases |
Catalysis |
Equilibrium |
Precipitation / Solubility
Chemical equilibrium (Nyman, Carl J.; Hamn, Randall E.)  Jekel, Eugene C.

Jekel, Eugene C. J. Chem. Educ. 1970, 47, A132.
Equilibrium
Analogies between chemical and mechanical equilibria  Canagaratna, S. G.; Selvaratnam, M.
The authors show that the concept of chemical equilibrium can, with advantage, be presented by drawing analogies with mechanical equilibria that students should be familiar with.
Canagaratna, S. G.; Selvaratnam, M. J. Chem. Educ. 1970, 47, 759.
Equilibrium
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
General chemistry experiments: Six short, inexpensive procedures  Heit, M. L.; Dauphinee, G. A.
These simple experiments involve conductivity comparisons of derivatives of the acetate ion, paper chromatography, sublimation, the effect of temperature on equilibrium, the detection of I-, and an example of an equilibrium shift.
Heit, M. L.; Dauphinee, G. A. J. Chem. Educ. 1970, 47, 532.
Electrochemistry |
Chromatography |
Phases / Phase Transitions / Diagrams |
Equilibrium |
Oxidation / Reduction
Prolonging death (in apples)  Plumb, Robert C.
Using controlled atmosphere storage to prolong the freshness of vegetables and fruits after they have been harvested.
Plumb, Robert C. J. Chem. Educ. 1970, 47, 518.
Equilibrium |
Kinetics |
Agricultural Chemistry |
Applications of Chemistry |
Gases
The use of specific ion electrodes for equilibrium measurements  Williams, T. R.; Boettner, Wayne; Wakeham, Stuart
The purpose of this investigation is to suggest the variety of information that can be obtained using specific ion electrodes.
Williams, T. R.; Boettner, Wayne; Wakeham, Stuart J. Chem. Educ. 1970, 47, 464.
Ion Selective Electrodes |
Equilibrium
Sealed tube experiments  Campbell, J. A.
Lists and briefly describes a large set of "sealed tube experiments," each of which requires less than five minutes to set-up and clean-up, requires less than five minutes to run, provides dramatic results observable by a large class, and illustrates important chemical concepts.
Campbell, J. A. J. Chem. Educ. 1970, 47, 273.
Thermodynamics |
Crystals / Crystallography |
Solids |
Liquids |
Gases |
Rate Law |
Equilibrium
Ratio diagrams: A simple graphical representation of complicated equilibria  de Levie, R.
Introduces and demonstrates the usefulness and general applicability of ratio diagrams as the simplest graphical representation of equilibria involving mononuclear species.
de Levie, R. J. Chem. Educ. 1970, 47, 187.
Equilibrium |
Acids / Bases |
pH |
Aqueous Solution Chemistry |
Precipitation / Solubility
Sunglasses that respond to brightness  Stookey, S. D.
Illustrating principles of chemical equilibrium
Stookey, S. D. J. Chem. Educ. 1970, 47, 176.
Equilibrium
Chemical principles exemplified  Plumb, Robert C.
Introduction to a new series, containing "exempla" (brief anecdotes about materials and phenomena which exemplify chemical principles). [Debut]
Plumb, Robert C. J. Chem. Educ. 1970, 47, 175.
Gases |
Kinetic-Molecular Theory |
Phases / Phase Transitions / Diagrams |
Thermodynamics |
Equilibrium |
Photochemistry |
Applications of Chemistry
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
The law of mass action  Berline, Steven; Bricker, Clark
It is the purpose of this paper to present a derivation of the Law of Mass Action that should have meaning and could be used at an elementary level.
Berline, Steven; Bricker, Clark J. Chem. Educ. 1969, 46, 499.
Equilibrium |
Rate Law |
Kinetics
A distribution experiment  Campbell, J. A.; Nelson, Douglas; Rudesill, John
An experiment to determine the distribution coefficient of an acid between an aqueous and nonaqueous phase.
Campbell, J. A.; Nelson, Douglas; Rudesill, John J. Chem. Educ. 1969, 46, 454.
Acids / Bases |
Aqueous Solution Chemistry |
Thermodynamics |
Equilibrium |
Titration / Volumetric Analysis
A computer program for the analysis of the N2O4 dissociation equilibrium  Erickson, Luther E.
Describes a Fortran IV program for the analysis of empirical data collected for the N2O4 dissociation equilibrium.
Erickson, Luther E. J. Chem. Educ. 1969, 46, 383.
Equilibrium |
Thermodynamics
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
Rapid graphical method for determining formation constants  Christian, Sherril D.
This paper presents a rapid graphical method for determining formation constants and absorptivities of 1:1 complexes in dilute solution.
Christian, Sherril D. J. Chem. Educ. 1968, 45, 713.
Equilibrium
Acid-base indicators: An experiment in aqueous equilibria  Brown, William E.; Campbell, J. A.
Examines absorbtivity values for six acid-base indicators under various conditions.
Brown, William E.; Campbell, J. A. J. Chem. Educ. 1968, 45, 674.
Acids / Bases |
Equilibrium |
Aqueous Solution Chemistry |
Spectroscopy |
UV-Vis Spectroscopy |
Dyes / Pigments
Calcium carbonate equilibria in lakes  Morton, Stephen D.; Lee, G. Fred
Discusses some of the problems encountered in studying the chemistry of lakes and oceans, focussing on the solubility of calcium carbonate in fresh water lakes.
Morton, Stephen D.; Lee, G. Fred J. Chem. Educ. 1968, 45, 511.
Aqueous Solution Chemistry |
Water / Water Chemistry |
Precipitation / Solubility |
Equilibrium
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
From stoichiometry and rate law to mechanism  Edwards, John O.; Greene, Edward F.; Ross, John
Examines the rules used by chemists as guidelines in developing mechanisms from stoichiometric and rate law observations.
Edwards, John O.; Greene, Edward F.; Ross, John J. Chem. Educ. 1968, 45, 381.
Stoichiometry |
Rate Law |
Kinetics |
Mechanisms of Reactions |
Equilibrium |
Reactive Intermediates
Reaction rates and equilibria. D. Redox  Klug, Evangeline B.
Sugar + chlorate + acid produces an exothermic reaction using a violent oxidizing agent.
Klug, Evangeline B. J. Chem. Educ. 1967, 44, A545.
Oxidation / Reduction |
Equilibrium
Reaction rates and equilibria. C. Equilibrium   Slabaugh, W. H.; Jackman, Kenneth V.
Demonstrations of the effect of temperature on equilibrium include shifting equilibrium by heating and cooling phosphorous pentabromide and cobalt complexes.
Slabaugh, W. H.; Jackman, Kenneth V. J. Chem. Educ. 1967, 44, A545.
Equilibrium
A simple analogy of the relationship of ?G to the position of equilibrium  Marks, D. J.
This short note describes a simple demonstration to serve as an analogy of the relationship of ?G to the position of equilibrium.
Marks, D. J. J. Chem. Educ. 1967, 44, 402.
Thermodynamics |
Equilibrium
Hard sphere simulation of statistical mechanical behavior of molecules  Plumb, Robert C.
Describes the design and use of a demonstration device to illustrate the kinetic behavior of gases, liquids, and solids.
Plumb, Robert C. J. Chem. Educ. 1966, 43, 648.
Statistical Mechanics |
Gases |
Liquids |
Solids |
Kinetic-Molecular Theory |
Equilibrium |
Phases / Phase Transitions / Diagrams
General solution of ionic equilibria problems: A computer program  Haglund, E.; Moss, D.; Flynn, J.
Presents a computer program for an iterative solution of a set of simultaneous equations describing an equilibrium system.
Haglund, E.; Moss, D.; Flynn, J. J. Chem. Educ. 1966, 43, 582.
Equilibrium
Principles of chemical equilibrium (Morris, Kelso B.)  Eblin, Lawrence P.

Eblin, Lawrence P. J. Chem. Educ. 1966, 43, 110.
Equilibrium |
Enrichment / Review Materials
Electrode potentials  Shombert, Donald
Changes in the potential observed for two Daniell cells are due to changes in ion concentrations.
Shombert, Donald J. Chem. Educ. 1965, 42, A215.
Electrochemistry |
Electrolytic / Galvanic Cells / Potentials |
Aqueous Solution Chemistry |
Equilibrium
A computer program for use in teaching chemical equilibrium  Zajicek, O. T.
Describes a computer program for use in teaching chemical equilibrium.
Zajicek, O. T. J. Chem. Educ. 1965, 42, 622.
Equilibrium |
Acids / Bases |
pH
The ionization of polyhydric acids: Numerical results for phosphoric acid  Cooke, S. L., Jr.
Presents calculated ionization values for phosphoric acid across the normal aqueous pH range.
Cooke, S. L., Jr. J. Chem. Educ. 1965, 42, 620.
Acids / Bases |
Equilibrium
Solvent effect on the keto-enol equilibrium of acetoacetic ester  Lockwood, Karl L.
The purpose of the investigation is to introduce students to some of the factors that influence an equilibrium constant.
Lockwood, Karl L. J. Chem. Educ. 1965, 42, 481.
Solutions / Solvents |
Equilibrium
Is the solubility product constant? Introductory experiment in solubility equilibrium  Goodman, Robert C.; Petrucci, Ralph H.
This article describes an experiment that employs the titration of lead nitrate solutions with potassium iodide solutions as a vivid and straightforward method of determining solubility product.
Goodman, Robert C.; Petrucci, Ralph H. J. Chem. Educ. 1965, 42, 104.
Equilibrium |
Precipitation / Solubility |
Aqueous Solution Chemistry
Teaching ionic equilibrium: Use of log chart transparencies  Freiser, Henry; Fernando, Quintus
The use of graphical methods brings the problem of significance of various terms in complicated expressions into proper focus. Furthermore, a pictorial representation permits the student to see at a glance how the concentrations of various species in a system at equilibrium change with conditions.
Freiser, Henry; Fernando, Quintus J. Chem. Educ. 1965, 42, 35.
Aqueous Solution Chemistry |
Equilibrium |
Acids / Bases |
pH |
Chemometrics |
Brønsted-Lowry Acids / Bases
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
Demonstration of a parent-daughter radioactive equilibrium using 137Cs-137mBa  Choppin, Gregory R.; Nealy, Carson L.
Demonstrates the relationship between radioactive half life and both the rate of decay and growth of a radioactive daughter.
Choppin, Gregory R.; Nealy, Carson L. J. Chem. Educ. 1964, 41, 598.
Isotopes |
Nuclear / Radiochemistry |
Equilibrium |
Rate Law
Automatic titrimetry in introductory college chemistry  Zajicek, O. T.
The experiment described here employs an automatic pH titrator as a tool for the teaching of a detailed treatment of simultaneous equilibria.
Zajicek, O. T. J. Chem. Educ. 1964, 41, 554.
Titration / Volumetric Analysis |
pH |
Aqueous Solution Chemistry |
Acids / Bases |
Equilibrium
Molecular equilibrium (Carnell, P. H.; Reusch, R. N.)  Loehlin, James H.
A programmed teaching aid.
Loehlin, James H. J. Chem. Educ. 1964, 41, 290.
Equilibrium |
Enrichment / Review Materials
Effect of chloride ion on precipitation of cadmium sulfide  O'Donnell, T. A.
Adding NaCl or KCl to suspended CdS causes the suspension to disappear.
O'Donnell, T. A. J. Chem. Educ. 1963, 40, A313.
Precipitation / Solubility |
pH |
Equilibrium
KineticsEarly and often  Campbell, J. A.
Describes an approach to investigating kinetics and its application to the "blue bottle" experiment.
Campbell, J. A. J. Chem. Educ. 1963, 40, 578.
Kinetics |
Equilibrium |
Mechanisms of Reactions
Heterogeneous equilibria in general chemistry  Grotz, Leonard C.
Presents suggestions for approaching the subject of heterogeneous equilibria in general chemistry.
Grotz, Leonard C. J. Chem. Educ. 1963, 40, 479.
Equilibrium |
Kinetics
Temperature dependence of equilibrium: A first experiment in general chemistry  Mahan, Bruce H.
This experiment uses cooling curves to derive the expression for the temperature dependence of the equilibrium constant.
Mahan, Bruce H. J. Chem. Educ. 1963, 40, 293.
Equilibrium |
Thermodynamics
Formation of monothiocyanatoiron(III): A photometric equilibrium study  Ramette, Richard W.
Presents a beginning equilibrium experiment using photometry.
Ramette, Richard W. J. Chem. Educ. 1963, 40, 71.
Photochemistry |
Equilibrium |
Spectroscopy
An experimental program on chemical equilibrium  Reusch, R. N.; Carnell, P. H.
Describes the development and evaluation of a program on chemical equilibrium
Reusch, R. N.; Carnell, P. H. J. Chem. Educ. 1963, 40, 27.
Equilibrium
Hypodermic syringes in quantitative elementary chemistry experiments. Part 2. General chemistry experiments  Davenport, Derek A.; Saba, Afif N.
Presents a variety of experiments that make use of hypodermic syringes in quantitative elementary chemistry.
Davenport, Derek A.; Saba, Afif N. J. Chem. Educ. 1962, 39, 617.
Laboratory Equipment / Apparatus |
Gases |
Liquids |
Reactions |
Equilibrium |
Stoichiometry
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
Equilibria in ionic solutions  Kokes, R. J.; Dorfman, M. K.; Mathia, T.
In conjunction with lectures on equilibria in electrolytic solutions, students perform a set of laboratory experiments in which they determine both the ionization constant of chloroacetic acid and the solubility of its silver salt.
Kokes, R. J.; Dorfman, M. K.; Mathia, T. J. Chem. Educ. 1962, 39, 93.
Equilibrium |
Aqueous Solution Chemistry |
Acids / Bases |
Precipitation / Solubility
Chemical equilibrium: The hydrogenation of benzene  Kokes, R. J.; Dorfman, M. K.; Mathia, T.
This procedure examines the reversible reaction between benzene and hydrogen, forming cyclohexane, in the presence of a metal catalyst.
Kokes, R. J.; Dorfman, M. K.; Mathia, T. J. Chem. Educ. 1962, 39, 91.
Reactions |
Aromatic Compounds |
Equilibrium |
Catalysis
Calculating molar solubilities from equilibrium constants  Butler, James N.
Presents several examples of calculating molar solubilities from equilibrium constants.
Butler, James N. J. Chem. Educ. 1961, 38, 460.
Chemical Technicians |
Equilibrium |
Stoichiometry |
Qualitative Analysis |
Aqueous Solution Chemistry
The equilibria of complex formation  Banks, James E.
Despite the present recognition of the stepwise formation of complexes in solution, many textbooks continue to treat it as a one-step process, presumably to preserve a reasonable simplicity in the mathematical computation of concentrations.
Banks, James E. J. Chem. Educ. 1961, 38, 391.
Equilibrium |
Coordination Compounds |
Aqueous Solution Chemistry
An approach to complex equilibrium problems  Butler, James N.
Presents an approach to equilibrium problems that sets up enough equations relating the various concentrations present to define the system completely and then makes approximations that simplify the equations.
Butler, James N. J. Chem. Educ. 1961, 38, 141.
Equilibrium |
Chemometrics |
Acids / Bases |
Aqueous Solution Chemistry
Dynamic equilibrium: A simple quantitative demonstration  Carmody, Walter R.
Transferring colored water between two graduated cylinders using pipets of varying sizes demonstrates the establishment of a dynamic equilibrium.
Carmody, Walter R. J. Chem. Educ. 1960, 37, 312.
Equilibrium
Potentiometric measurements of equilibria: In general chemistry laboratory  Chesick, J. P.; Patterson, Andrew, Jr.
The authors describe an experiment in which the solubility product of silver chloride, the ionization constant of the silver-ammonia complex, and the ionization constant of acetic acid can be determined with one afternoon of work.
Chesick, J. P.; Patterson, Andrew, Jr. J. Chem. Educ. 1959, 36, 496.
Electrochemistry |
Equilibrium |
Precipitation / Solubility |
Aqueous Solution Chemistry |
Acids / Bases
Dynamic equilibrium: A student demonstration  Kauffman, George B.
Dynamic equilibrium is demonstrated by students pouring water back and forth between containers using different sized beakers.
Kauffman, George B. J. Chem. Educ. 1959, 36, 150.
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
Textbook errors: Guest column. The solubility product constants of the metallic sulfides  Waggoner, William H.
This report reviews direct and indirect methods for investigating the solubility of substances, including conductance, potentiometric, optical, equilibrium, and thermodynamic procedures.
Waggoner, William H. J. Chem. Educ. 1958, 35, 339.
Precipitation / Solubility |
Equilibrium |
Metals |
Conductivity
The analyst and the inconstant constants  Ringbom, Anders
Simple theories taught to freshmen often do not agree well with experimental data; the author examines the case of equilibrium constants and elaborates on a method of dealing with this problem.
Ringbom, Anders J. Chem. Educ. 1958, 35, 282.
Equilibrium |
Aqueous Solution Chemistry |
Precipitation / Solubility
Textbook errors: Guest column. XVI: The vapor pressure of hydrated cupric sulfate  Logan, Thomas S.
Examines variability in the values of pressures of water vapor in equilibrium with pairs of cupric sulfate in hydrates quoted in the literature and texts.
Logan, Thomas S. J. Chem. Educ. 1958, 35, 148.
Phases / Phase Transitions / Diagrams |
Equilibrium
Demonstration of dynamic nature of ions using I131  Blake, Richard F.
This demonstration presents visual evidence of the ionic nature of solid salts and the dynamic equilibrium existing between dissolved and undissolved ions.
Blake, Richard F. J. Chem. Educ. 1956, 33, 354.
Isotopes |
Aqueous Solution Chemistry |
Solids |
Precipitation / Solubility |
Equilibrium
Textbook errors: VII. The laws of reaction rates and of equilibrium  Mysels, Karol J.
Examines the frequently misplaced emphasis on the rate law of mass action, its fallacious use to prove the existence and form of equilibrium constants, and the occasional confusion of the two concepts.
Mysels, Karol J. J. Chem. Educ. 1956, 33, 178.
Kinetics |
Rate Law |
Equilibrium
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
Solubility of silver salts in aqua ammonia  Johnson, Clyde R.
Examines two problems regarding the calculation of the solubility of a silver salt in aqua ammonia of a given concentration.
Johnson, Clyde R. J. Chem. Educ. 1954, 31, 205.
Precipitation / Solubility |
Equilibrium
Praseodymium tetrafluoride  Perros, Theodore P.; Munson, Thomas R.; Naeser, Charles R.
In spite of the experimental failures to prepare praseodymium tetrafluoride, there is strong evidence for its possible formation to be found by calculating the equilibrium constants for some of the reactions by which this compound might be prepared.
Perros, Theodore P.; Munson, Thomas R.; Naeser, Charles R. J. Chem. Educ. 1953, 30, 402.
Oxidation State |
Equilibrium |
Thermodynamics
A procedure for solving equilibrium problems  Boyd, Robert Neilson
A procedure for solving equilibrium problems is illustrated through several sample problems.
Boyd, Robert Neilson J. Chem. Educ. 1952, 29, 198.
Equilibrium |
Chemometrics |
Aqueous Solution Chemistry
A temperature-equilibrium demonstration  Brown, John A.
This demonstration makes use of the colored cobaltous complexes in a mixed solvent to show the dependence of some equilibria on temperature.
Brown, John A. J. Chem. Educ. 1951, 28, 640.
Equilibrium |
Calorimetry / Thermochemistry |
Thermodynamics |
Coordination Compounds
Some lecture demonstrations in general chemistry  Klemm, L. H.
Describes three demonstrations involving the atomistic nature of matter, the controlled experiment, and the solubility product.
Klemm, L. H. J. Chem. Educ. 1951, 28, 587.
Kinetic-Molecular Theory |
Aqueous Solution Chemistry |
Precipitation / Solubility |
Equilibrium