Question

Write equation for the reactions taking place at two electrodes mentioning clearly the name of electrode during the electrolysis of:-

ii) Molten lead bromide with inert electrode.

Answer 1

${\mathrm{PbBr}}_2$ $\mathrm{undergoes}\mathrm{dissociation}\mathrm{reaction}:-$

${\mathrm{PbBr}}_2\rightleftharpoons {\mathrm{Pb}}^{2+}+2{\mathrm{Br}}^{-}$

At Cathode:-

${\mathrm{Pb}}^{2+}+2{\mathrm{e}}^{-}\to \mathrm{Pb}$

At Anode:-

$2{\mathrm{Br}}^{-}-2{\mathrm{e}}^{-}\to {\mathrm{Br}}_2\left(\mathrm{g}\right)$

Here both anode and cathode are made up of graphite as it is not affected by Bromine$\left(Br\right)$ vapors.