Solving Acid-Base Equilibrium Problems

By John T. Moore

Part of Chemistry II For Dummies Cheat Sheet

The acid and base equilibrium constant expressions describe the relationship between the amounts of reactants and products in aqueous acid-base systems. For the following general weak-acid equilibrium:


the equilibrium constant expression is:


For a general weak-base equilibrium:


the equilibrium constant expression is:


The concentration of water (or any pure liquid or solvent or solid) does appear in the equilibrium constant expression. K is the equilibrium constant, the subscript b indicates that this is an equilibrium constant expression for a weak base, and the brackets indicate molar concentrations.