Question

Why does blue colour of copper sulphate solution starts fading when a zinc rod is dipped in it ?

Answer 1

Blue color of CuSO₄ fades when zinc rod is dipped in it. This happens because zinc is higher up in the reactivity series than copper. So zinc reacts with the solution displacing copper to form ZnSO₄and the Cu metal gets deposited over the rod. The ZnSO₄ solution is colourless and hence due to the formation of this solution the blue color starts fading. The following chemical recation takes place.

Zn + CuSO₄ → ZnSO₄ + Cu