Question

what is meant buy water of crystallisation in a substance how would you show that blue copper sulphate crystals contain water of crystallisation

Answer 1

Water of crystallization is explained in pic
But just it simply means water molecules which form part of substance of crystallization

Answer 2

It is the fixed number of water molecules present in a one formula unit of salt.
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by performing the activity give below:
1. Heat few copper crystals in a test tube
Observation: we will see few droplets on the mouth of test tube and the color of salt turns white.