Question

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

Answer 1

Electrolysis is a process of separating the compounds in its constituents elements by passing the electricity.

1.When molten lead bromide with inert electrodes is electrolysed it will dissociate into lead ion and bromide ion.

$$\begin{gathered} {\mathrm{PbBr}}_2\to {\mathrm{Pb}}^{2+}+2{\mathrm{Br}}^{-} \\ \mathrm{lead}\mathrm{bromide}\mathrm{lead}\mathrm{ion}\mathrm{bromide}\mathrm{ion} \end{gathered}$$

2.The cathode and anode both are made of graphite electrodes.

At anode: The bromide ions loses the electron and by combining itself to liberate bromine gas.

$$\begin{gathered} {\mathrm{Br}}^{-}\to \mathrm{Br}+{\mathrm{e}}^{-} \\ \mathrm{Br}+\mathrm{Br}\to {\mathrm{Br}}_2\uparrow \\ \mathrm{bromine}\mathrm{gas} \end{gathered}$$

At cathode: The lead ions gets reduced to lead atom.

$$\begin{gathered} {\mathrm{Pb}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Pb} \\ \mathrm{lead}\mathrm{ion}\mathrm{lead}\mathrm{atom} \end{gathered}$$