$= + 0.34 \,volt, I_2/ 2I- = + 0.53\, volt$
$Cu ( s )+ Sn ^{2+}( aq ) \rightarrow Cu ^{2+}( aq )+ Sn ( s )$
$\left( E _{ Sn ^{2+} \mid Sn }^{0}=-0.16\, V , E _{ Cu ^{2+} \mid Cu }^{0}=0.34\, V \right.$ Take $F=96500\, C\, mol ^{-1}$ )
$Mn^{2+} +2e- \rightarrow Mn;\, E^o = -1.18\,V$
$2(Mn^{3+} +e^- \rightarrow Mn^{2+} )\,;\,E^o=+1.51\,V$
તો $3Mn^{2+} \rightarrow Mn+ 2Mn^{3+}$ માટે $E^o$ કેટલો થશે ?