Question

12. a. Why copper sulphate is known as a hydrated salt? How can its colour be changed? Is it a physical or chemical​

Answer 1

${\huge{ \boxed {\sf \red{Answer}}}}$

The blue colour of copper sulphate is due to water of hydration. When heated, it loses two water molecules at ~63°C followed by two more at ~109°C and the final water molecule at ~200°C and turns to white coloured anhydrous copper sulphate. The above process can be reversed.

Hope it helps