What is the change in oxidation number of Pb | vedclass

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(D) In a lead storage battery acting as a galvanic cell (discharging), the positive electrode is $PbO_2$.At the positive electrode, the reduction reac

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decreases by $2$

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(D) In a lead storage battery acting as a galvanic cell (discharging), the positive electrode is $PbO_2$.At the positive electrode, the reduction reaction is: $PbO_2(s) + SO_4^{2-}(aq) + 4H^+(aq) + 2e^- \rightarrow PbSO_4(s) + 2H_2O(l)$.In $PbO_2$, the oxidation number of $Pb$ is $+4$.In $PbSO_4$, the oxidation number of $Pb$ is $+2$.Change in oxidation number = $+2 - (+4) = -2$.Thus, the oxidation number decreases by $2$.

What is the change in oxidation number of $Pb$ at the positive electrode of a lead accumulator acting as a galvanic cell?

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