(Solved): An electrochemical cell consists of a standard hydrogen electrode and a copper metal electrode. \[ ...

An electrochemical cell consists of a standard hydrogen electrode and a copper metal electrode. \[ \mathrm{Cu}^{2+}+2 \mathrm{e}^{-} \rightarrow \mathrm{Cu} \quad E^{\circ}=0.34 \mathrm{~V} \] a. What is the potential of the cell at \( 25^{\circ} \mathrm{C} \) if the copper electrode is placed in a solution in which \( \left[\mathrm{Cu}^{2+}\right]=2.4 \times 10^{-4} M \) ? \[ E_{\text {cell }}=\quad \quad \mathrm{V} \] b. The copper electrode is placed in a solution of unknown \( \left[\mathrm{Cu}^{2+}\right] \). The measured potential at \( 25^{\circ} \mathrm{C} \) is \( 0.191 \mathrm{~V} \). What is \( \left[\mathrm{Cu}^{2+}\right] \) ? (Assume \( \mathrm{Cu}^{2+} \) is reduced.) \[ \left[\mathrm{Cu}^{2+}\right]=\quad M \]