d
\(2Cu^{+} \to Cu + Cu^{+2}\)          \(E^o_3 =\) ??  \(n_{3} = ??\)

(વિષમ પ્રમાણન પ્રક્રિયા )

\(C{u^{ + 2}}\, + \,\,{e^ - }\,\, \to \,\,C{u^ + }\)         \({E^ o }\, = \,\,0.15\,volt\)

\(C{u^ + }\, \to \,\,C{u^ {+2} }\, + \,\,{e^ - }\)          \({E^o }\, = \,\, - \,\,0.15\,\,volt\)

અથવા \(2C{u^{ + 1}}\, \to \,\,2C{u^{ + 2}}\,+\,2{e^ - }\)     \(E_1^o \, = \,\, - 0.15\,\,volt,\,\,{n_1}\, = \,\,2\)

\(C{u^{ + 2}}\, + \,\,2{e^ - }\, \to \,\,Cu\)      \(E_2^ o \,\, = \,\,0.34\,\,volt,\,\,{n_2}\, = \,\,2\)

\(\therefore \,\,E_3^o \,\, = \,\,\frac{{ - 0.15\,\, \times \,\,2\,\, + \,\,0.34\,\, \times \,\,2}}{1}\,\, = \,\,0.38\,\,volt\)

જ્યારે \(\text{E}_{\text{3}}^{o}\) એધન છે જેથી \({\text{C}}{{\text{u}}^ + }\) એ જલીય માધ્યમમાં હાજર નથી .