Amongst the following electrodes,the one with zero electrode potential is

What is the oxidation and reduction potential of standard hydrogen electrode?

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

The reaction is spontaneous if the cell potential is

Which of the following metals does not release $H_{2(g)}$ upon reaction with acid?

The $E^{\ominus}$ for $Cl_{2}/Cl^{-}$ is $+1.36 \ V,$ for $I_{2}/I^{-}$ is $+0.53 \ V,$ for $Ag^{+}/Ag$ is $+0.79 \ V,$ $Na^{+}/Na$ is $-2.71 \ V$ and for $Li^{+}/Li$ is $-3.04 \ V.$ Arrange the following ionic species in decreasing order of reducing strength: $I^{-}, Ag, Cl^{-}, Li, Na$