# Solubility product

In a saturated solution of sparingly soluble electrolyte two equilibria exist and can be represented as, _{} ⇌ _{}⇌ _{}

Applying the law of mass action,_{}

Since the solution is saturated, the concentration of unionised molecules of the electrolyte is constant at a particular temperature, i.e., _{} constant.

Hence, _{} (constant)

_{} is termed as the solubility product. It is defined as the product of the concentration of ions in a saturated solution of an electrolyte at a given temperature.

Consider, in general, the electrolyte of the type _{} which dissociates as, _{}⇌ _{}

Applying law of mass action, _{}

When the solution is saturated, _{} (constant) or

_{} (constant)

Thus, solubility product is defined as the product of concentrations of the ions raised to a power equal to the number of times the ions occur in the equation representing the dissociation of the electrolyte at a given temperature when the solution is saturated.