The standard electrode potential for the half-cell reactions are
$Zn^{2+} + 2e^{-} \longrightarrow Zn ; E^{\circ} = -0.76 \ V$
$Fe^{2+} + 2e^{-} \longrightarrow Fe ; E^{\circ} = -0.44 \ V$
The $emf$ of the cell reaction,
$Fe^{2+} + Zn \longrightarrow Zn^{2+} + Fe$ is

Consider the following reduction processes:
$Al^{3+} + 3e^{-} \rightarrow Al_{(s)}, E^{\circ} = -1.66 \ V$
$Fe^{3+} + e^{-} \rightarrow Fe^{2+}, E^{\circ} = +0.77 \ V$
$Co^{3+} + e^{-} \rightarrow Co^{2+}, E^{\circ} = +1.81 \ V$
$Cr^{3+} + 3e^{-} \rightarrow Cr_{(s)}, E^{\circ} = -0.74 \ V$
The tendency to act as a reducing agent decreases in the order:

If the half-cell reaction $A + e^- \to A^-$ has a large negative reduction potential,it follows that

The standard reduction potentials of three metals $A, B,$ and $C$ are $+0.5 \, V, -3.0 \, V,$ and $-1.2 \, V$ respectively. What is the order of their reducing power?

Which electrode is used to measure the electrode potential of any electrode?

The relation between $\Delta G$ and $E$ for a cell is $\Delta G = -nFE$. The cell reaction will be spontaneous if: