For the given cell;
$$
\mathrm{Cu}(\mathrm{~s})\left|\mathrm{Cu}^{2+}\left(\mathrm{C}_1 \mathrm{M}\right) \| \mathrm{Cu}^{2+}\left(\mathrm{C}_2 \mathrm{M}\right)\right| \mathrm{Cu}(\mathrm{~s})
$$
change in Gibbs energy ( $\Delta \mathrm{G}$ ) is negative, if