The salts which contain water molecules are known as hydrated salts. For example the crystals of copper sulphate contain five molecules of water called water of crystallization. So the formula of hydrated salt of copper sulphate is CuSO4.5H2O.
Water of Crystallization
The molecules of water which combine chemically with the molecule of a salt are called the water of crystallization.For example, each molecule of washing soda contains 10 molecules of water of crystallization.
Anhydrous Salts
The salts which don’t contain water molecules are known as anhydrous salts. For example, if we heat the crystals of copper sulphate then the five molecules of water will evaporate, and the remaining salt without water will be called as anhydrous salt having formula CuSO4.
Strong acids:
CuSO4.5H2O CuSO4 + 5H20
Anhydrous copper
Sulphate
Test your understanding and answer these questions:
- What are hydrated salts? Give examples.
- What do you understand by water of crystallization?