Which of the following has the least tendency to liberate $H_2$ from mineral acids?

The standard oxidation potentials for the half-reactions are given as $Zn \to Zn^{2+} + 2e^{-}; E^o = +0.76 \ V$ and $Fe \to Fe^{2+} + 2e^{-}; E^o = +0.41 \ V$. The $EMF$ for the cell reaction $Fe^{2+} + Zn \to Zn^{2+} + Fe$ is ............ $V$.

For the spontaneity of a cell,which of the following is correct?

The standard reduction potentials at $25^o \text{C}$ for $Li^{+}/Li$,$Ba^{2+}/Ba$,$Na^{+}/Na$,and $Mg^{2+}/Mg$ are $-3.05 \ V$,$-2.73 \ V$,$-2.71 \ V$,and $-2.37 \ V$ respectively. Which of the following is the strongest oxidizing agent?

Calculate $E_{\text{cell}}^{\circ}$ for $Cd_{(s)}|Cd^{2+}_{(1M)}||Ag^{+}_{(1M)}|Ag_{(s)}$. Given: $E^{\circ}_{Cd^{2+}/Cd} = -0.403 \ V$ and $E^{\circ}_{Ag^{+}/Ag} = 0.799 \ V$. (in $V$)

For four metals $A, B, C$ and $D$,the standard reduction potentials are $-3.05 \ V, -1.66 \ V, -0.40 \ V$ and $0.80 \ V$ respectively. Which metal exhibits the highest chemical reactivity?