JCE Software, 6B1: Equilibrium Calculator

Equilibrium Calculator

Robert D. Allendoerfer
State University of New York at Buffalo, Buffalo, NY 14214-3094

Note:
Series B (MS DOS) software previously included on the General Chemistry Collection CD-ROM is now available for free download by Journal of Chemical Education subscribers.
Go to the download page.

Equilibrium Calculator, adapted from a previously published computer program (1), has the potential to eliminate quadratic equations from general chemistry books as calculators have eliminated logarithm tables. Many current textbooks limit the discussion of the calculation of equilibrium concentrations to a few carefully chosen examples that can be treated using only second order polynomials, e.g., PCl₅ PCl₃ + Cl₂, because these are the only type of problems that students can solve exactly.

Screen from Equilibrium Calculator.

Equilibrium Calculator can calculate the equilibrium concentrations of all the reagents in an arbitrary chemical reaction with as many as five reactants and products:
a A + b B + c C + d D + e E = v V + w W + x X + y Y + z Z
without the necessity of solving polynomial equations. The program works by minimizing the Gibbs Free Energy as a function of the extent of reaction using an iterative algorithm. This method for single step equilibria (2, 3) has been extended to competing and coupled reactions (4).
The input data are:

The stoichiometric coefficients in the balanced equation
The initial concentrations of the chemical species
The equilibrium constant, Kc
Thus by using this program, chemically relevant examples such as the production of ammonia from nitrogen and hydrogen, can be introduced into general chemistry without regard to mathematical difficulty.
Hardware and Software Requirements
Equilibrium Calculator requires an IBM PS/2, PC, or PC-compatible microcomputers with 640K of RAM and one floppy disk drive. CGA or compatible graphics and PC- or MS-DOS 3.1 or later are also required.
Literature Cited

Juan Miguel Campanario and Reyes Ballesteros, J. Comp. Math. Sci. Teaching, 1991, 10 (2), 87.
E. Weltin, J. Chem. Educ., 1990, 67 (7), 548.
E. Weltin, J. Chem. Educ., 1991, 68(6), 486.
E. Weltin, J. Chem. Educ., 1992, 69 (5), 393.

First Published: April 1993
Citation: Allendoerfer, R. D. . Equilibrium Calculator J. Chem. Educ. Software 6B1
Keywords: Lecture Aid; Computer Room; Laboratory; Instructor; High School; General; Analytical; Laboratory; Equilibrium calculations

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JCE Online | Journal | Software | Internet | Happenings | About JCE | Contact JCE

Last Updated: April 26, 2001
Created: December 4, 1996 Created by: J. L. Holmes
Comments to: jceonline@chem.wisc.edu

© 1997 Division of Chemical Education, Inc., American Chemical Society. All rights reserved.



Equilibrium Calculator
Robert D. Allendoerfer State University of New York at Buffalo, Buffalo, NY 14214-3094

Note:	Series B (MS DOS) software previously included on the General Chemistry Collection CD-ROM is now available for free download by Journal of Chemical Education subscribers. Go to the download page.

Equilibrium Calculator, adapted from a previously published computer program (1), has the potential to eliminate quadratic equations from general chemistry books as calculators have eliminated logarithm tables. Many current textbooks limit the discussion of the calculation of equilibrium concentrations to a few carefully chosen examples that can be treated using only second order polynomials, e.g., PCl₅ PCl₃ + Cl₂, because these are the only type of problems that students can solve exactly. Screen from Equilibrium Calculator. Equilibrium Calculator can calculate the equilibrium concentrations of all the reagents in an arbitrary chemical reaction with as many as five reactants and products: a A + b B + c C + d D + e E = v V + w W + x X + y Y + z Z without the necessity of solving polynomial equations. The program works by minimizing the Gibbs Free Energy as a function of the extent of reaction using an iterative algorithm. This method for single step equilibria (2, 3) has been extended to competing and coupled reactions (4). The input data are: The stoichiometric coefficients in the balanced equation The initial concentrations of the chemical species The equilibrium constant, Kc Thus by using this program, chemically relevant examples such as the production of ammonia from nitrogen and hydrogen, can be introduced into general chemistry without regard to mathematical difficulty. Hardware and Software Requirements Equilibrium Calculator requires an IBM PS/2, PC, or PC-compatible microcomputers with 640K of RAM and one floppy disk drive. CGA or compatible graphics and PC- or MS-DOS 3.1 or later are also required. Literature Cited Juan Miguel Campanario and Reyes Ballesteros, J. Comp. Math. Sci. Teaching, 1991, 10 (2), 87. E. Weltin, J. Chem. Educ., 1990, 67 (7), 548. E. Weltin, J. Chem. Educ., 1991, 68(6), 486. E. Weltin, J. Chem. Educ., 1992, 69 (5), 393.


News \| Issues \| CD-ROM / Video \| Find It! \| Technical Support \| For Authors
JCE Online \| Journal \| Software \| Internet \| Happenings \| About JCE \| Contact JCE

Last Updated: April 26, 2001 Created: December 4, 1996	Created by: J. L. Holmes Comments to: jceonline@chem.wisc.edu

© 1997 Division of Chemical Education, Inc., American Chemical Society. All rights reserved.