Condition of precipitation

Ionic product ($IP$) of an electrolyte is defined in the same way as solubility product ($K_{sp}$). The only difference is that the ionic product expression contains concentration of ions under any condition whereas expression of $K_{sp}$ contains only equilibrium concentrations. If,

a. $IP = K_{sp}$ ; the solution is saturated and solubility equilibrium exists.

b. $IP > K_{sp}$ ; the solution is supersaturated and hence precipitation of the compound will occur. …