Question

What is the colour of anhydrous copper sulphate? Why is it so?

Answer 1

Before heating, the colour of copper sulphate is blue, due to presence of water of crystaliization (CuSO₄.5H₂O), but after heating it becomess white, as it looses the five molecules of water of crystallization. The source of water droplets is the crystallisation water of copper sulphate. Hence, the colour of anhydrous copper sulphate is white.