Question

Write the cell reactions which occur in a lead storage battery when the battery is on charging.

Answer 1

At negative electrode: \[\ce{PbSO4_{(s)} + 2e- ->[direct current] Pb_{(s)} + SO^{2-}_{4(aq)}}\]

At positive electrode: \[\ce{PbSO4_{(s)} + 2H2O ->[direct current] PbO2_{(s)} + 4H{^{+}_{(aq)}} + SO^{2-}_{4 (aq)} + 2e-}\]

Overall charging reaction: \[\ce{\underset{(present on the electrodes)}{2PbSO4_{(s)}} + 2H2O ->[Charging] \underset{recovered)}{\underset{(electrode materials)}{Pb_{(s)} + PbO2_{(s)}}} + \underset{(H2SO4)}{4H{^{+}_{(aq)}}} + 2SO^{2-}_{4(aq)}}\]