$2H^{+} \, (aq) + 2e^- \to H_2 \, (g)$. The standard electrode potential for the above reaction is (in volts):

If standard reduction potentials $(E^0)$ of $(Al^{+3}_{(aq)}|Al(s))$, $(Fe^{+2}_{(aq)}|Fe(s))$, $(Cu^{+2}_{(aq)}|Cu(s))$ and $(Ag^{+1}_{(aq)}|Ag(s))$ are $-1.66 \text{ V}$, $-0.44 \text{ V}$, $+0.34 \text{ V}$ and $+0.79 \text{ V}$ respectively, which of the following reactions is non-spontaneous?

Using the standard electrode potential values,which of the following statements $(I, II, III, IV)$ is/are correct?
$Fe^{2+}_{(aq)} + 2e^{-} \rightleftharpoons Fe_{(s)}$ ; $E^o = -0.44 \, V$
$Cu^{2+}_{(aq)} + 2e^{-} \rightleftharpoons Cu_{(s)}$ ; $E^o = +0.34 \, V$
$Ag^{+}_{(aq)} + e^{-} \rightleftharpoons Ag_{(s)}$ ; $E^o = +0.80 \, V$
$I$. Copper displaces iron from $FeSO_4$ solution.
$II$. Iron displaces copper from $CuSO_4$ solution.
$III$. Silver displaces copper from $CuSO_4$ solution.
$IV$. Iron displaces silver from $AgNO_3$ solution.

Give the symbolic representation of the following half-cells (electrodes):
$(i)$ $Zn_{(s)} | Zn^{2+}_{(aq)} (1M)$
$(ii)$ $Cu^{2+}_{(aq)} (1M) | Cu_{(s)}$
$(iii)$ $Pt_{(s)} | H_{2(g)} (1 \text{ bar}) | H^+_{(aq)} (1M)$

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 of the following has the highest electrode potential?