Question

How many molecules of water of crystallisation (per formula unit) are present in :

(a) copper sulphate crystals ?

(b) washing soda ?

(c) gypsum ?

Answer 1

1. Copper Sulphate ($CuS{O}_4.5H_{2}O$ ): 5 molecules of water of crystallization.

2. Washing soda ($N{a}_{2}C{O}_3.10H_{2}O$ ): 10 molecules of water of crystallization

3. Gypsum ($CaS{O}_4.2H_{2}O$): 2 molecules of water of crystallization