If the standard electrode potential of ${\mathrm{Cu}}^{2+}/\mathrm{Cu}$ electrode is 0.34 V, what is the electrode potential at 0.01 M concentration of ${\mathrm{Cu}}^{2+}?$$\left(\mathrm{T}={298}^{\circ }\mathrm{K}\right)$

Reduction of copper 

${\mathrm{Cu}}^{2+}+\hspace{0.17em}2{\mathrm{e}}^{-}\to \mathrm{Cu}$

Electrode potential can be calculated using Nernst equation: 

$$\begin{gathered} {\mathrm{E}}_{\mathrm{cell}}={\mathrm{E}}_{\mathrm{cell}}^{\mathrm{o}}-\frac{0.0591}{\mathrm{n}}\log \frac{1}{\left[{\mathrm{Cu}}^{2+}\right]} \\ =0.34-\frac{0.0591}{2}\log \frac{1}{{10}^2} \\ {\mathrm{E}}_{\mathrm{cell}}=0.281 \mathrm{V} \end{gathered}$$