Question

What do you understand by water of crystallization ?
Give four substances which contain water of crystallization and write their common names.

Answer 1

Some salts, while crystallizing out from their solutions, unite with definite quality of water which is known as water of crystallization.
For substances which contain water of crystallization:
$N{a}_{2}C{O}_3.10H_{2}O$ Waqshing soda
$MgS{O}_4.7H_{2}O$ Epsom salt