When ${\text{CuSO}}_4.5{\text{H}}_2\text{O}$ is heated, the products formed are:

The correct option is C $CuS{O}_{4}and5H_{2}O$
Hydrated copper sulphate $\left({\text{CuSO}}_4.5{\text{H}}_2\text{O}\right)$ is blue in colour. When it is heated, compound loses its water of crystallization. Hence, the colour of the compound changes from blue to white as it breaks apart to form anhydrous ${\text{CuSO}}_4$ and ${\text{H}}_2\text{O}$. The reaction involved is:

${\text{CuSO}}_4.5{\text{H}}_2\text{O(s)}\stackrel{\text{Heat}}{\rightleftharpoons }{\text{CuSO}}_4\text{(s)}+{\text{5H}}_2\text{O(l)}$