Solubility Product

The Solubility Product, K_s, is the equilibrium constant for the equilibrium that exists between a slightly soluble salt and its ions in a saturated solution. For example,

AgCl_(s) = Ag⁺_(aq) + Cl^-_(aq)

K_s = [Ag⁺_(aq)][Cl^-_(aq)] K_s = 1.74 x 10^-10 mol² dm^-6

Solubility product and 'solubility' are different and must not be confused. Unlike the solubility of a substance, the solubility product is independent of what else is dissolved in solution. The solubility of a substance can be calculated from its solubility product.

See also Equilbrium Constant.