On charging the lead storage battery,the oxidation state of lead changes from $x_1$ to $y_1$ at the anode and from $x_2$ to $y_2$ at the cathode. The values of $x_1, y_1, x_2, y_2$ are respectively $:$

Calculate $\Delta G^{\circ}$ for the reaction $Mg_{(s)} + Sn_{(aq)}^{2+} \longrightarrow Mg_{(aq)}^{2+} + Sn_{(s)}$ if $E_{cell}^{\circ}$ is $2.23 \ V$. (in $kJ$)

The Gibbs energy change (in $J$) for the given reaction at $[Cu^{2+}] = [Sn^{2+}] = 1 \, M$ and $298 \, K$ is:
$Cu_{(s)} + Sn^{2+}_{(aq)} \rightarrow Cu^{2+}_{(aq)} + Sn_{(s)}$
$(E^{\circ}_{Sn^{2+}|Sn} = -0.16 \, V, E^{\circ}_{Cu^{2+}|Cu} = 0.34 \, V, F = 96500 \, C \, mol^{-1})$

Which of the following is incorrect in a galvanic cell?

Give the chemical reaction when a $Cu$ rod is kept in an $AgNO_{3}$ solution.

Which among the following equations represents the reduction taking place in a lead accumulator at the positive electrode,while it is being used as a source of electrical energy?