alleryLead-acid battery during DISCHARGE: PbO2 + Pb + 2H2SO4 → 2PbSO4 + 2H2O. The role of PbO2 is:
AInert
BCATHODE (reduction; PbO2 → PbSO4)
CAnode (oxidation)
DElectrolyte
Answer & Solution
Correct answer: B. CATHODE (reduction; PbO2 → PbSO4)
PbO2 (Pb in +4 state) → PbSO4 (Pb in +2 state): reduction.
So PbO2 is the cathode.
Pb metal is anode (Pb → Pb²⁺ → PbSO4, oxidation).
Voltage about 2 V per cell.
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