Question

The standard emf for the given cell reaction, $Zn+C{u}^{2+}⟶Cu+Z{n}^{2+}$ is $1.10V$ at $25^{\circ }C$. The emf for the cell reaction, when $0.1MC{u}^{2+}$ and $0.1MZ{n}^{2+}$ solutions are used at $25^{\circ }C$ is

• A. 1.10 V
• B. -1.10 V
• C. 2.20 V
• D. -2.20 V

Answer 1

Answer: (A)

$E_{\text{cell }}=E_{\text{cell }}^{\circ }-\frac{0.059}{2}\log \frac{\left[Z{n}^{2+}\right]}{\left[C{u}^{2+}\right]}$
$=1.10-\frac{0.059}{2}\log \frac{0.1}{0.1}$
$=1.10V$