$(i)\, Cu^{2+} + 2e^- \rightarrow Cu\,,$ $ E^o = 0.337\, V$
$(ii)\, Cu^{2+} + e^- \rightarrow Cu^+\,,$ $ E^o = 0.153\, V$
તો પ્રક્રિયા $Cu^+ + e^- \rightarrow Cu$ માટે $E^o$........... $V$ થશે.
For reaction, $C u^{2+}+2 e^{-} \rightarrow C u$
$\Delta G^{0}=-2 \times F \times 0.337 \ldots(i)$
For reaction, $C u^{+} \rightarrow C u^{2+}+e^{-}$
$\Delta G^{0}=-1 \times F \times 0.153 \quad \dots(i i)$
Adding Eqs. (i) and (ii), we get
$C u^{+}+e^{-} \rightarrow C u, \Delta G^{0}=-0.521 F$
$\Delta G^{0}=-n F E^{0}-0.521 F=-n F E^{0}$
$\therefore E^{0}=0.52 V$
તાપમાન $\quad$ સંતુલન અચળાંક
$\begin{array}{ll} T _{1}=25^{\circ} C & K _{1}=100 \\ T _{2}=100^{\circ} C & K _{2}=100\end{array}$
$T _{1}$ તાપમાને $\Delta H ^{\circ}, \Delta G ^{\circ}$ના મૂલ્યો અને $T _{2}$ તાપમાને $\Delta G ^{\circ}$નું મૂલ્ય ($kJ\, mol ^{-1}$ માં) અનુક્રમે , નજીક હશે?
$\left[\right.$ ઉપયોગ કરો : $\left. R =8.314\, JK ^{-1} mol ^{-1}\right]$
$Zn(s)\, + \,C{u^{2 + }}(aq)\, \to \,Z{n^{2 + }}(aq) + Cu\,(s)$
$(298\,K$ પર ${E^o} = 2\,V,$ ફેરાડે અચળાંક $F = 96500\, C\, mol^{-1})$
${[Fe\,{(CN)_6}]^{4 - }}\, \to \,{[Fe{(CN)_6}]^{3 - }}\, + \,{e^ - }\,;\,$ ${E^o}\, = \, - \,0.35\,V$
$\,F{e^{2 + }}\, \to \,F{e^{3 + }}\, + \,{e^ - }\,;$ ${E^o}\, = \, - \,0.77\,V$