If $Cu^{+} + e^- \to Cu$ ; $E^o = X_1$ and $Cu^{2+} + 2e^- \to Cu$ ; $E^o = X_2$,then the value of $E^o$ for $Cu^{2+} + e^- \to Cu^{+}$ will be:

Aluminium displaces hydrogen from dilute $HCl$ whereas silver does not. The e.m.f. of a cell prepared by combining $Al/Al^{3+}$ and $Ag/Ag^{+}$ is $2.46 \ V$. The reduction potential of silver electrode is $+0.80 \ V$. The reduction potential of aluminium electrode is $........... \ V$.

The standard electrode potential of the cell $H_2 | H^{+} || Ag^{+} | Ag$ is .......... $V$.

Given $E^{0}_{Fe^{3+}|Fe} = -0.036 \, V$ and $E^{0}_{Fe^{2+}|Fe} = -0.439 \, V$,the standard electrode potential for the reaction $Fe^{3+}_{(aq)} + e^{-} \rightarrow Fe^{2+}_{(aq)}$ is ........... $V$.

The standard reduction potentials at $298 \ K$ for the following half-cell reactions are given below:
$Zn^{2+}_{(aq)} + 2e^{-} \rightleftharpoons Zn_{(s)} : -0.762 \ V$
$Cr^{3+}_{(aq)} + 3e^{-} \rightleftharpoons Cr_{(s)} : -0.74 \ V$
$2H^{+}_{(aq)} + 2e^{-} \rightleftharpoons H_{2(g)} : 0.00 \ V$
$Fe^{3+}_{(aq)} + e^{-} \rightleftharpoons Fe^{2+}_{(aq)} : 0.77 \ V$
Which one of the following is the strongest reducing agent?

Which of the following metals behaves as the weakest reducing agent?
$E^\circ_{(\text{Li}^+/\text{Li})} = -3.05 \text{ V}$, $E^\circ_{(\text{Au}^{3+}/\text{Au})} = 1.40 \text{ V}$, $E^\circ_{(\text{Ag}^+/\text{Ag})} = 0.80 \text{ V}$, $E^\circ_{(\text{Mg}^{2+}/\text{Mg})} = -2.36 \text{ V}$