d
(d)The required reaction \((C{u^{ + + }} + Cu \to 2C{u^ + })\) can be obtained by using the following reactions.

\(C{u^{ + + }} + {e^ - } \to C{u^ + };\,\,\,E_{C{u^{ + + }}/C{u^ + }}^o = 0.15\,\,V\,\,\) …..\((i)\)

\(C{u^{ + + }} + 2{e^ - } \to Cu;\,\,\,\,E_{C{u^{ + + }}/Cu}^o = 0.\,34\,\,V\,\) …..\((ii)\)

Multiplying eq. \((i)\) by \(2\) we get

\(2C{u^{ + + }} + 2{e^ - } \to 2C{u^ + }\) …..\((iii)\)

\(\Delta {G_1} = - nFE = - 2 \times F \times 0.15\)

\(C{u^{ + + }} + 2{e^ - } \to Cu\,\,\,\)…..\((iv)\)

\(\Delta {G_2} = - nFE = - 2 \times F \times 0.34\)

Subtract the eq. \((iv)\) from \( (iii)\)

\(C{u^{ + + }} + Cu \to 2C{u^ + }\)

\(\Delta {G_3} = - \,nFE = - 1 \times F \times {E^o}\)

Also \(\Delta {G_3} = \Delta {G_1} - \Delta {G_2}\)

\( - 1F{E^o} = ( - \,2F \times 0.15) - ( - \,2F \times 0.34)\) \({E^o} = - \,0.38\)

This is the value for the reaction

\(C{u^{ + + }} + Cu \to 2C{u^ + }\)

But the given reaction is just reverse of it

\({E_{{\rm{cell}}}}\) for given reaction \(= + 0.38\,V.\)