Standard electrode potentials are given:
$A^{+}/A = -2.93 \ V$ $B^{+}/B = 0.80 \ V$
$C^{2+}/C = -2.37 \ V$ $D^{3+}/D = -0.74 \ V$
Increasing order of reducing power of these metals:

If the standard reduction potentials of four electrodes $A$, $B$, $C$, and $D$ are $+2.5 \text{ V}$, $+3.0 \text{ V}$, $-2.0 \text{ V}$, and $-1.5 \text{ V}$ respectively, in which case is the standard $emf$ of the cell maximum?

Which of the following metals will not evolve $H_2$ gas from dilute $H_2SO_4$ solution?

The standard Gibbs energy for the given cell reaction in $kJ \, mol^{-1}$ at $298 \, K$ is $Zn_{(s)} + Cu^{2+}_{(aq)} \to Zn^{2+}_{(aq)} + Cu_{(s)}$,given $E^o = 2 \, V$ at $298 \, K$ [Faraday's constant $F = 96500 \, C \, mol^{-1}$].

How would you determine the standard electrode potential of the system $Mg^{2+} | Mg$?

The standard electrode potentials of two half-cells are given as: $Ni^{2+}_{(aq)} + 2e^{-} \rightarrow Ni_{(s)}$; $E^o = -0.25 \ V$ and $Zn^{2+}_{(aq)} + 2e^{-} \rightarrow Zn_{(s)}$; $E^o = -0.76 \ V$. What is the standard $emf$ of the cell formed by connecting these two half-cells in $volt$?