$Cu^+_{(aq)} + e^- \rightarrow Cu_{(s)}$ માટે વિધુતધ્રુવ પોટેન્શિયલ અનુક્રમે $+ 0.15\, V$ તથા $+ 0.50\, V$ છે. $E^o_{Cu^{2+}/Cu}$ ....... $V$ થશે.
\(E_{1}^{0}=0.15 V, \Delta G_{1}^{0}=-n_{1} E_{1}^{0} F\)
\(\frac{ C u^{+}+e^{-} \rightarrow C u, E_2^0=0.50 V, \Delta G_{2}^{0}=-n_{2} E_{2} P}{C u^{2+}+2 e^{-} \rightarrow C u, E^{0}=7, \Delta G^{0}=-n E^{0} F}\)
\(\Delta G^{0}=\Delta G_{1}^{0}+\Delta G_{2}^{0}\)
\(-n E^{0} F=-n_{1} E_{1}^{0} F-n_{2} E_{2}^{0} F\)
or \(-2 E^{0} F=-1 F \times 0.15+(-1 F \times 0.50)\)
or \(-2 E^{0} F=-0.15 F-0.50 F\)
or \(-2 F E^{0}=-F(0.15+0.50)\)
\(\therefore \quad E^{0}=\frac{0.65}{2}=0.325 V\)
$Fe^{+2} + Zn \rightarrow Zn^{+2} + Fe$
$Zn \rightarrow Zn^{+2} + 2e^{-}$ અને $E^{0} = 0.76$ વૉલ્ટ,
$Fe \rightarrow Fe^{+2} + 2e^{-}$ અને $E^{0} = 0.41 $વૉલ્ટ
(નજીકનાં પૂર્ણાંકમાં રાઉન્ડ ઑફ). $\left[\right.$ આપેલ $, E_{C u^{2+} / C u}^{o}=0.34\, V , E _{ NO _{3}^{-} / NO_2 }^{\circ}=0.96\, V$ $,E _{ NO _{3} / NO _{2}}^{\circ}=0.79 \,V$ $\left.\frac{ RT }{ F }(2.303)=0.059\right]$
(આપેલ છે: $\mathrm{E}_{\mathrm{Sn}^{2+} / \mathrm{Sn}}^{0}=-0.14 \mathrm{\;V}$ $\left.\mathrm{E}_{\mathrm{Pb}^{+2}/{\mathrm{Pb}}}^{0}=-0.13 \;\mathrm{V}, \frac{2.303 \mathrm{RT}}{\mathrm{F}}=0.06\right)$