# The standard reduction potential for $Cu^+ / Cu$ an $Cu^{2+} /Cu^+$ are $0.337\;V$ and $0.153\;V$ respectively . The standard electrode potential of $Cu^+/Cu$ half cell is
$\begin{array}{1 1} 0.184\;V \\ 0.827\;V \\ 0.521\;V \\ 0.490 \;V \end{array}$