• # question_answer The blue colour of copper sulphate solution is discharged when a rod of zinc is dipped in it. Explain.

Zinc lies below copper in the electrochemical series and can therefore, release electrons to the $C{{u}^{2+}}$ ions. As a result, Zn is oxidised while $C{{u}^{2+}}$ ions are reduced. Since the concentration of $C{{u}^{2+}}$ ions in the solution decreases, the blue colour of the solution is slowly discharged. $Zn(s)+C{{u}^{2+}}(aq)\xrightarrow{\,}Z{{n}^{2+}}(aq)+Cu(s)$