The standard reduction potentials of Pb and Zn electrodes are -0.126 and -0.763 volts respectively. The cell equation will be

Question

The standard reduction potentials of $\mathrm{Pb}$ and $\mathrm{Zn}$ electrodes are -0.126 and -0.763 volts respectively. The cell equation will be

(A) $\mathrm{Pb}^{2+}+\mathrm{Zn} \rightarrow \mathrm{Pb}+\mathrm{Zn}^{2+}$

(B) $\mathrm{Pb}+2 \mathrm{Zn}^{2+} \rightarrow \mathrm{Pb}^{4+}+2 \mathrm{Zn}$

(C) $\mathrm{Zn}^{2+}+\mathrm{Pb} \rightarrow \mathrm{Zn}+\mathrm{Pb}^{2+}$

(D) none of the above.

Answer 1

The $E^{\circ}{ }_{\text {red }}$ of $\mathrm{Zn}$ is lower than that of $\mathrm{Pb}$, hence $\mathrm{Zn}$ is a better reducing agent than $\mathrm{Pb}$.

$\therefore \quad$ The correct cell reaction will be

$\mathrm{Pb}^{2+}+\mathrm{Zn} \rightarrow \mathrm{Pb}+\mathrm{Zn}^{2+}$

So, The correct option is (A).