State what happens when:
$(a)$ Hydrated copper sulphate is heated.
Also,write the chemical equation for the reaction.

(N/A) When hydrated copper sulphate $(CuSO_4 \cdot 5H_2O)$ is heated,the five molecules of water of crystallisation are lost,and the blue-coloured crystals turn into a white anhydrous powder.
If we add water back to this white powder,the blue colour reappears due to the re-formation of hydrated copper sulphate.
The chemical equation is:
$CuSO_4 \cdot 5H_2O (s) \xrightarrow{\text{Heat}} CuSO_4 (s) + 5H_2O (g)$
(Blue) $\quad \quad \quad \quad \quad \quad \quad \quad$ (White)