Chapter 15: Equilibrium - K, Q, and ICE charts

The study of chemical equilibria often uses ICE charts. ICE charts help us to keep track of the Initial conditions of a chemical reaction, the Change that the reaction undergoes to reach equilibrium, and the Equilibrium conditions. The equilibrium constant, K, is a useful tool for analyzing chemical equilibria. K allows us to determine when a reaction is at equilibrium or not. To do this, we calculate Q, the reaction quotient, which has the same form as K. However, K can only be calculated at equilibrium while Q can be calculated for any conditions. If K = Q, the reaction is at equilibrium. If Q is less than K, the reaction must proceed toward products to reach equilibrium. If Q is greater than K, the reaction must proceed toward reactants to reach equilibrium.