What happens when a saturated solution is cooled?
A.It becomes unsaturated
B.It remains unaffected
C.It becomes supersaturated
D.It becomes transparent

Hint: Saturated solution is the one that contains the maximum amount of solute at a given temperature. On cooling the saturated solution its solubility decreases which results in the separation of some of the dissolved substance or solute in the solid crystal form.

Complete step by step answer:
Temperature has its effect on saturated solutions i.e. heating or cooling a saturated solution will lead to some changes in it. On decreasing the temperature of a saturated solution or cooling it basically the solubility of the solute decreases. It starts forming crystals and settles down at the bottom of the container or vessel. This results in the formation of a supersaturated solution. Cooling of solution results in the loss of kinetic energy of solvent or liquid due to which they come closer and as a result solute molecules are pushed away leading to the formation of crystals which then decreases the solubility, so a supersaturated solution is formed.

Hence, the correct choice is (C).

Note:
The heating of saturated solutions lead to the increase in their solubility. The kinetic energy of the liquid molecules increases on increasing the temperature due to which they move apart from each other creating more space for the solute molecules to dissolve thereby increasing the solubility. So a solution becomes unsaturated on heating while supersaturated on cooling. Sodium acetate is an example of supersaturated solution.