# Precipitation Reactions > [!abstract] Precipitation Reactions > A **precipitation reaction** involves multiple dissolved substances which react to form one (or more) solid products. > - *Also known as: Double Displacement, Double Replacement, & Metathesis* --- Solubility is the maximum concentration of a substance that can be achieved under specified conditions. - A substance will **precipitate** when it’s concentration exceeds its solubility within the given solution. --- Substances that have a relatively large solubility are said to be **soluble**. Substances that have a relatively low solubility are said to be **insoluble**; these are the substances which readily precipitate from the solution. You can use the standard set of [[Solubility vs Dissociation]] to predict the solubility of a substance --- Where dissolved substances react to form one (or more) solid products - Also referred to as double displacement ### Solubility Product Constant Solubility constants are the equilibrium constants for precipitation reactions $M_pX_q (s) \rightleftharpoons pM^{m+} (aq) + qX^{n-} (aq)$ $K_{sp} = [M^{m+p}]^p \cdot [X^{n-}]^q$