Common Ion Effect

When an ion involved in a \(K_{sp}\) equilibrium equation reaction, is also found in the surrounding solution the solubility of the solid can vary.

E.g. Reaction dependent on pH

Calculating

If you have an insoluble compound in a solution with a common ion, the concentration of the solution is involved in the ICE table

pH can also be converted into a concentration for these equilibria reactions

Order of Precipitation

If there are multiple insoluble ionic compounds with the same common ion and differing \(K_{sp}\) values they will precipitate at different concentrations of the common ion

Fractional Precipitation