The common ion effect for ionic solids (salts) is to decrease the solubility of the ionic compound in water significantly. explain the common ion effect in detail.

Explanation has been given below.

Explanation:

Let's consider solubility equilibrium of an ionic insoluble compound e.g.

Equilibrium constant of this solubility equilibrium is represented in terms of solubility product () which is expressed as-

Now, if we add an ionic salt e.g. with a common ion then concentration of increases.

But, at a constant temperature, is constant.

Therefore, to keep constant, excess amount of will combine with free ion in solution and produce .

Hence, as a whole, solubility of decreases.