MHT CET20244 May 2024Morning ShiftChemistryElectrochemistryActual
Which of the following reactions occurs at cathode during discharging of lead accumulator?
Options
- APbSO _ 4( ~s ) +2 e ⁻ Pb _ ( s ) + SO _ 4 (aq.) ²⁻
- BPb _ ( s ) + SO _ 4( (aq. ) ²⁻ PbSO _ 4( ~s ) +2 e ⁻
- CPbO _ 2( ~s ) +4 H _ ( aq ) ⁺+ SO _ 4( aq ) ²⁻+2 e ⁻ PbSO _ 4(s) +2 H ₂ O _ (1)
- DPbSO _ 4( ~s ) +2 H ₂ O _ (1) PbO _ 2( ~s ) +4 H _ ( aq .) ⁺+ SO _ 4( aq .) ²⁻+2 e ⁻
Correct answer
C. PbO _ 2( ~s ) +4 H _ ( aq ) ⁺+ SO _ 4( aq ) ²⁻+2 e ⁻ PbSO _ 4(s) +2 H ₂ O _ (1)
Step-by-step solution
During the discharge of a lead-acid battery, the cathode reaction involves lead dioxide ( PbO ₂ ) reacting with sulfuric acid to form lead sulfate ( PbSO ₄ ) and water, while releasing electrons. The correct reaction at the cathode is: PbO ₂+4 H ⁺+ SO ₄²⁻+2 e⁻ PbSO ₄+2 H ₂ O Thus, the correct answer is (3).