Question

how impure copper sulphate can be purified by crystelisation

Answer 1

Impure copper sulphate can be purified by the method of crystallisation to obtain pure copper sulphate.This is done as follows : 1.Take about 10 grams of impure copper sulphate and dissolve it in minimum amount of water in a china dish to make copper sulphate solution.

Answer 2

impure copper sulphate can be purified by crystallisation in the following ways:
1.first take impure copper sulphate solution in a beaker and start heating it till it gets saturated
2.take the beaker and put a filter paper on it and let the solution to rest overnight 
3.the following day you can observe copper sulphate crystals separated from the impurities.