Procedure of purification of impure copper sulphate by crystallization-

1) Impure copper sulphate is dissolved in minimum amount of water.

2) The solution is filtered to remove insoluble impurities.

3) The clear solution is heated gently on a water bath till a concentrated solution or saturated solution is obtained.

4) Allow the hot ,saturated solution to cool slowly.

5) Crystals of pure copper sulphate are formed. Impurities remain dissolved in solution.

6) Separate the crystals of pure Copper sulphate by filtration and dry them.