ICE Tables:
Introduction

Some general rules always apply when constructing ICE tables.

1. Since the entries in the I and E rows represent amounts of substances, these numbers must always be zero or positive. Since it makes no sense to have a negative amount, concentration, or pressure of something, negative numbers are not allowed.
2. To help fill out the C row accurately, be sure the chemical equation at the top of the table is balanced. The entries in the C row must be related by the correct stoichiometric factor or mole ratio (see the Stoichiometry tutorial).
3. When the amount of reactants is decreasing, the amount of products must be increasing. Conversely, when the amount of products is increasing, the amount of reactants must be decreasing. Therefore, in the C row, the reactants and products always have opposite signs.
4. The entries in the E row are always the sum of the corresponding entries in the I and C rows.