Which is the increasing order of reducing power of the following metals on the basis of standard electrode potential? $Ag^{+}/Ag = 0.80 \ V$,$Mg^{2+}/Mg = -2.37 \ V$,$Hg^{2+}/Hg = 0.79 \ V$,$Cr^{3+}/Cr = -0.74 \ V$

For the feasibility of a redox reaction in a cell,the e.m.f. should be

From the following ${E^o}$ values of half cells,what combination of two half cells would result in a cell with the largest potential?
$I$. $A + e^- \to A^{-}$,${E^o} = +0.24 \ V$
$II$. $B^{-} + e^- \to B^{-2}$,${E^o} = +1.25 \ V$
$III$. $C^{-} + 2e^- \to C^{-3}$,${E^o} = +0.15 \ V$
$IV$. $D + 2e^- \to D^{-2}$,${E^o} = +0.68 \ V$

Given:
$E^o_{Cr^{3+}/Cr} = -0.74 \ V$,$E^o_{MnO_4^-/Mn^{2+}} = 1.51 \ V$
$E^o_{Cr_2O_7^{2-}/Cr^{3+}} = 1.33 \ V$,$E^o_{Cl_2/Cl^{-}} = 1.36 \ V$
Based on the data given above,the strongest oxidising agent will be:

Electrode potential of $Zn^{2+}/Zn$ is $-0.76\,V$ and that of $Cu^{2+}/Cu$ is $+0.34\,V$. The $EMF$ of the cell constructed between these two electrodes is ............ $V$.

Which expression represents the cell potential $(E_{cell})$?