SAT Subject Test Chemistry




Chemical Equilibrium

Chapter Summary

The following terms summarize all the concepts and ideas that were introduced in this chapter. You should be able to explain their meaning and how you would use them in chemistry. They appear in boldface type in this chapter to draw your attention to them. The boldface type also makes it easier for you to look them up if you need to. You could also use the search or “Google” action on your computer to get a quick and expanded explanation of these terms, laws, and formulas.

acid ionization constant

equilibrium constant

common ion effect

free energy

enthalpy (ΔH)

Gibbs free-energy equation

entropy (ΔS)

solubility product constant


Le Châtelier’s Principle

Second Law of Thermodynamics

Internet Resources

Online content that reinforces major concepts discussed in this chapter can be found at the following Internet addresses if they are still available. Some may have been changed or deleted.

Le Châtelier’s Principle

This site gives an explanation of the principle. This site also provides specific examples of how the principle can be used in different circumstances to show the effects of changing temperature, pressure, and concentration on an equilibrium system.

Equilibrium Equations and Constants

This site offers tutorials and exercises on how to work with equilibrium equations and constants along with exercises and answers to equilibrium problems.


This site offers a unique approach to investigate entropy and the second law of thermodynamics as a dialogue between a student and teacher.