Which one of the following metals cannot evolve $H_2$ from acids,$H_2O$,or from its compounds?

Given:
$E^o_{Fe^{3+} /Fe} = -0.036 \ V, E^o_{Fe^{2+} /Fe} = -0.439 \ V$
The value of standard electrode potential for the change,
$Fe^{3+}_{(aq)} + e^- \rightarrow Fe^{2+}_{(aq)}$ will be ........ $V$.

Which among the following species is reduced by tin easily?

If the standard reduction potentials of $Zn$, $Ni$, and $Fe$ are $-0.76 \text{ V}$, $-0.23 \text{ V}$, and $-0.44 \text{ V}$ respectively, determine the electrodes $X$ and $Y$ for the reaction $X(s) + Y^{+2}_{(aq)} \rightarrow X^{+2}_{(aq)} + Y(s)$ to be spontaneous.

$E^{\circ}$ of $Cu$ is $+0.34 \ V$ while that of $Zn$ is $-0.76 \ V$. Explain.

Given $E^{\circ} Mn^{7+} / Mn^{2+} = 1.51 \ V$ and $E^{\circ} Mn^{4+} / Mn^{2+} = 1.23 \ V$. Calculate $E^{\circ} Mn^{7+} / Mn^{4+}$. (in $V$)