Question

Blue color compound 'X' changes to white color compound 'Y' on heating and when we moisten compound 'Y', blue color of compoumd 'X' reappers. This is because compound 'X' has some water of crystallisation.

• A. True
• B. False

Answer 1

The correct option is A True

Compound 'X' is $CuS{O}_4.5H_{2}O$. When X is heated, the water molecules disappear and X looses its blue color and become 'Y' which is $CuS{O}_4$ (anhydrous). When $CuS{O}_4$ is mostened i.e. reacted with water, it takes water molecule as water of crystallisation and the blue color reappers.