$2 \mathrm{H}_{(\mathrm{aq})}^{+}+2 \mathrm{e}^{-} \rightarrow \mathrm{H}_2(\mathrm{~g})$
${\left[\mathrm{H}^{+}\right]=1 \mathrm{M}, \mathrm{P}_{\mathrm{H}_2}=2 \mathrm{~atm}}$
(Given: $2.303 \mathrm{RT} / \mathrm{F}=0.06 \mathrm{~V}, \log 2=0.3$ )
$Mn^{2+} +2e- \rightarrow Mn;\, E^o = -1.18\,V$
$2(Mn^{3+} +e^- \rightarrow Mn^{2+} )\,;\,E^o=+1.51\,V$
તો $3Mn^{2+} \rightarrow Mn+ 2Mn^{3+}$ માટે $E^o$ કેટલો થશે ?