${{\text{E}}^o }{\text{C}}{{\text{u}}^{{\text{2}} + }}{\text{/Cu = + 0}}{\text{.34 V, E}}_{{\text{F}}{{\text{e}}^{ + {\text{2}}}}/Fe}^o = \,\,{\text{ - 0}}{\text{.44 V}}$
$F{e^2}+ \left( {aq} \right) + A{g^ + }\left( {aq} \right) \to F{e^{3 + }}\left( {aq} \right) + Ag\left( s \right)$
$E_{Ag^+/Ag}^o = xV$, $E_{F{e^{2 + }}/Fe}^o = yV$, $E_{F{e^{3 + }}/Fe}^o = zV$
$E^o_{Cr_2/O_7^{2-}/Cr^{3+}}=1.33\,V,$ $E^o_{MnO^-_4/Mn^{2+}} = 1.51\,V$
તો નીચેના પૈકી સૌથી પ્રબળ રિડક્શતકર્તા ..........