Calculating Solubility Equilibrium Problems

By John T. Moore

Part of Chemistry II For Dummies Cheat Sheet

The solubility product equation is used to describe the equilibrium situation when a not-so-soluble salt is dissolving in water. For the general dissociation of a sparingly soluble salt:


In this equation, x+ and z– are the magnitude of the positive and negative charge, respectively; the equilibrium constant expression (solubility product expression) is

Ksp = [Mx+]a[Xz]b