Question

What is meant by water of crystallisation of a substance? Describe an activity to show that.

Answer 1

Water of crystallization is the fixed number of molecules which are present in one formula unit of salt.

Activity-
Aim: To show the water of crystallization
Materials required: Copper sulphate, bunsen burner, china dish. Procedure: Put some copper sulphate crystals on china dish and heat it with bunsen burner.
Observation: The blue colour crystals of copper sulphate changes to white powder on removal of 5 molecules of water of crystallization.
Equation: ${\text{CuSO}}_4.5{\text{H}}_2\text{O}$ $\to {\text{CuSO}}_4$
Conclusion: Colour change shows water of crystallization.