Question

Which reaction occurs at the cathode of a lead-storage battery that is being recharged?

Answer 1

PbSO4 + 2e- -> Pb +SO42-

Step-by-step explanation:

Pb +SO42- -> PbSO4 + 2e- is the reaction that occurs at the anode when discharging. So, when recharging, this reaction occurs at the cathode, but in reverse.

Answer 2

Reaction on positive electrode (cathode):
PbSO₄₍s₎ + 2H₂O₍l₎ → 2e⁻ + PbO₂₍s₎ + 4H⁺₍aq₎ + SO₄²⁻₍aq₎.
s - solid.
l - liquid.
aq - dissolve in water.
PbSO4 is converted to Pb at one electrode (anode) and to PbO₂ at the other (cathode). Lead battery can be recharged, during recharging, an external source of energy is used.