Question

Write equations for the reactions taking place at the two electrodes (mentioning clearly the name of the electrode) during the electrolysis of:
(i) Acidified copper sulphate solution with copper electrodes.
(ii) Molten lead bromide with inert electrodes.

Answer 1

(i) At the anode, oxidation reaction takes place: $Cu-2e^{-}\to C{u}^{2+}$

At cathode, reduction reaction occurs: $C{u}^{2+}+2e^{-}\to Cu$

Here, both are copper electrodes.

(ii) At anode:

$B{r}^{-}-e^{-}\to Br$

$Br+Br\to B{r}_2$

At cathode : $P{b}^{2+}+2e^{-}\to Pb$

Here, both anode and cathode are made up of graphite as it is unaffected by bromine vapours.