MHT CET202620 April 2026Morning ShiftChemistryElectrochemistryActual
Which of the following reactions occurs at cathode during recharging of lead accumulator ?
Options
- APbO _ 2(s) + 4 H ^+_ (aq.) + SO ₄²⁻ _ (aq.) + 2e^- Pb _ (s) + PbSO _ 4(s) + 2 H ₂ O _ ( )
- BPbO _ 2(s) + 4 H ^+ 2e^- Pb ²⁺ + 2 H ₂ O _ ( )
- CPb _ (s) + SO ₄²⁻ _ (aq.) PbSO _ 4(s) + 2e^-
- DPbSO _ 4(s) + 2e^- Pb _ (s) + SO ₄²⁻ _ (aq.)
Correct answer
D. PbSO _ 4(s) + 2e^- Pb _ (s) + SO ₄²⁻ _ (aq.)
Step-by-step solution
During the discharging of a lead accumulator, the cell acts as a galvanic cell with the following reactions: At anode (oxidation): Pb _ (s) + SO ₄²⁻ _ (aq.) PbSO _ 4(s) + 2e^- At cathode (reduction): PbO _ 2(s) + SO ₄²⁻ _ (aq.) + 4 H ^+_ (aq.) + 2e^- PbSO _ 4(s) + 2 H ₂ O _ ( ) During recharging, an external voltage is applied and the cell acts as an electrolytic cell. The reactions are reversed. The electrode that acted as the anode during discharge becomes the cathode (where reduction occurs), and the electrode t