Question

Write the chemical formula of hydrated copper sulphate and anhydrous copper sulphate. Give an activity to illustrate how these two are inter convertible.

Answer 1

Hydrated Copper sulphate$\Rightarrow CuS{O}_4.5H_{2}O$

Anhydrous Copper Sulphate$\Rightarrow CuS{O}_4$

Activity to show they are interconvertible:

$\underset{\left(Blue\right)}{CuS{O}_4.5H_{2}O}\stackrel{△}{\underset{H_{2}O}{\rightleftharpoons }}\underset{\left(White\right)}{CuS{O}_4}$

When hydrated $CuS{O}_4$ is heated in boiling tube, the water of crystallization is lost. The salt turns white.

However, again when crystals are moistened with water the blue color reappears. This is how they are interconvertible.