Which metal cannot produce $H_2$ gas by reaction with $HCl$ solution?
$E^0_{Fe^{2+}/Fe} = -0.44 \ V$
$E^0_{Cu^{2+}/Cu} = +0.34 \ V$
$E^0_{Ni^{2+}/Ni} = -0.25 \ V$
$E^0_{Zn^{2+}/Zn} = -0.76 \ V$

Which reference electrode is used to measure the electrode potential of other electrodes?

The $E^o$ values of half-cells are given below. Which combination of two half-cells will form a cell with the maximum potential?
$(i)$ $A + e^- \rightarrow A^- ; E^o = -0.24 \ V$
$(ii)$ $B^- + e^- \rightarrow B^{2-} ; E^o = +1.25 \ V$
$(iii)$ $C^- + 2e^- \rightarrow C^{3-} ; E^o = -1.25 \ V$
$(iv)$ $D + 2e^- \rightarrow D^{2-} ; E^o = +0.68 \ V$

If the $E^{0}$ values for $Mg^{+2} | Mg$,$Zn^{+2} | Zn$,and $Fe^{+2} | Fe$ are $-2.37 \ V$,$-0.76 \ V$,and $-0.44 \ V$ respectively,which statement is correct?

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

Given the standard half-cell potentials $(E^{\circ})$ as: $Zn \rightarrow Zn^{2+} + 2e^{-}$; $E^{\circ} = +0.76 \ V$ and $Fe \rightarrow Fe^{2+} + 2e^{-}$; $E^{\circ} = +0.41 \ V$. Then the standard e.m.f. of the cell with the reaction $Fe^{2+} + Zn \rightarrow Zn^{2+} + Fe$ is: