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

What will be the $EMF$ of the cell formed by the following half-cells in $V$?
$Mg^{2+} + 2e^- \to Mg_{(s)}; E = -2.37 \ V$
$Cu^{2+} + 2e^- \to Cu_{(s)}; E = +0.33 \ V$

Consider the reaction $M_{(aq)}^{n+} + n e^{-} \to M_{(s)}$. The standard reduction potential values of the elements $M_1$,$M_2$,and $M_3$ are $-0.34 \ V$,$-3.05 \ V$,and $-1.66 \ V$ respectively. The order of their reducing power will be

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

On the basis of the following $E^o$ values,the strongest oxidizing agent is:
$[Fe(CN)_6]^{4-} \to [Fe(CN)_6]^{3-} + e^-; E^o = -0.35 \ V$
$Fe^{2+} \to Fe^{3+} + e^-; E^o = -0.77 \ V$

What is the relationship between Gibbs free energy of the cell reaction in a galvanic cell and the emf of the cell? When will the maximum work be obtained from a galvanic cell?