$ = \,\,129.8\,\, + \,\,248.1\,\, - \,\,126.4$
$\mu _{N{H_4}OH}^\infty \, = \,\,251.5\,\,oh{m^{ - 1}}\,c{m^2}\,mo{l^{ - 1}}$
$(i)\, Cu^{2+} + 2e^- \rightarrow Cu\,,$ $ 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.