Number of molecules of water of crystallization in copper sulphate, sodium carbonate and Gypsum are

The correct answer is 5, 10 and 2 respectively.

• The number of molecules of water of crystallization in copper sulphate, sodium carbonate and Gypsum are 5, 10 and 2 respectively.

Key Points

• The water of crystallization is the water that occurs in the crystals. 
• Sodium carbonate (Na₂CO₃.10 H₂O) contains 10 water molecules.
• Sodium carbonate is also known as washing soda.
• It is called sodium carbonate decahydrate.
• Copper Sulphate (CuSO₄. 5 H₂O) contains 5 water molecules this is the reason why crystals of copper sulphate appear blue.
• Gypsum (CaSO₄ . 2 H₂O)  contains 2 water molecules.
• The chemical name of gypsum is calcium sulphate dehydrate.

Additional Information

• Sodium carbonate is used in cleaning products, and glass production, as a food additive.
• Copper sulfate is used as a fungicide, algaecide and herbicide in both agriculture and non-agricultural settings. 
• Gypsum is used to manufacture wallboard, cement, plaster of Paris, soil conditioning, a hardening retarder in portland cement.