A solution which remains in equilibrium with undissolved solute , in contact , is said to be saturated . The concentration of a saturated solution at a given temperature is a called solubility . The product of concentration of ions in a saturated solution of an electrolyte at a given temperature is called solubility product `(K_(sp))` . For the electrolyte `A_(x),B_(y)` with solubility S. The solubility product `(K_(sp))` is given as `K_(sp) = x^(x) xx y^(y) xx S^(x-y)` . While calculating the solubility of a sparingly . soluable salt in the presence of some strong electrolyte containing a common ion , the common ion concentration is practically equal to that of strong electrolyte containing a common ion . the common ion soncentration is practically equal to that of strong electrolyte . If in a solution , the ionic product of an electroylte exceeds its `K_(sp)` value at a particular temperature , then precipitation occurs . If two or more electrolyte are presentt in the solution , then by the addition of some suitable reagent , precipitation generally occurs in increasing order of their `k_(sp)` values . Solubility of some sparingly soluable salts , is sometimes enhanced through complexation . While we are calculating the solubility of some sparingly or pH of an electrolyte , the nature of cation of anion should be checked carefully whether there ion (s) are capable of undergoing hydrolysis or not . If either or both of the ions are capable of undergoing hydrolysis , it should be taken into account in calculating the solubility . While calculating the pH of an amphiprotic species , it should be checked whether or not cation can undergo hydrolysis . Total `a_(H^(-)) = sqrt(K_(a_(1)xxK_(a_(2))))` (if cation do not undergo hydrolysis ) ` a_(H^(+)) = sqrt(K_(a_(1))((K_(w))/(K_(b)) - K_(a_(2))))` (if cation also undergoes hydrolysis ) where symbols have usual meaning . Solubility of solids into liquids is a function of temperature alone but solubility of gases into liquids is a function of temperature as well as pressure . The effect of pressure on solubility of gases into liquids is governed by Henry's law . The solubility of `PbSO_(4)` in water is `0.0303` g/l at `25^(@)C` , its solubility product at that temperature is