ICE Tables:
Equilibrium

Goals: After completing this module you should be able to:

• Set up and use ICE tables to solve equilibrium problems.

Using an ICE table in equilibrium problems is similar to using one in stoichiometry problems, but with two important differences:

• Concentrations (or pressures for solely gas phase equilibria) are used instead of moles.
• Since equilibrium reactions never produce solely reactants or products, some of the information in the table may be unknown and represented by a variable. In this case, more information must be provided to calculate the value of the unknown and to solve the problem.

That being said, the steps to follow in completing an equilibrium ICE table are very similar to those that are followed in completing a stoichiometry ICE table.

Step 1: Write a balanced chemical equation describing the reaction in the problem.

Step 2: Convert any amounts you are given information about in the problem to concentration (or pressure) and insert in the appropriate cells in the table.

Step 3: Fill in an entry in the C row, using a variable to represent a change in concentration, if necessary.

Step 4: Complete the ICE table.

Step 5a: If necessary, solve an equation using the variable you introduced in step 3.

Step 5: Interpret the information in the ICE table to answer the question.

In this module, an ICE table will be set up using these steps and used to solve the following problem.

Before working through this problem, first take the time to answer the following questions.