\[ \ln k = \ln A - \frac{E_a}{R} . \frac{1}{T} \]
Comparing this with the straight-line equation \( y = mx + c \), the slope \( m = -\frac{E_a}{R} \)
\[ \text{Slope} = -\frac{E_a}{R} = -2 \times 10^4 \]
\[ \Rightarrow \frac{E_a}{R} = 2 \times 10^4 \Rightarrow E_a = R . 2 \times 10^4 = 8.3 . 2 \times 10^4 = 1.66 \times 10^5~\text{J mol}^{-1} \]
\[ = \frac{1.66 \times 10^5}{1000} = 166~\text{kJ mol}^{-1} \]
166 kJ mol\(^{-1}\)
\( \Delta G^\circ \, (\text{in kJ mol}^{-1}) \text{ for the cell reaction is} \)
\( \text{Cu}^{2+}(aq) + \text{Fe}(s) \rightarrow \text{Fe}^{2+}(aq) + \text{Cu}(s) \)
\( \left[\text{Given} \, E^\circ_{\text{Cu}^{2+}/\text{Cu}} = 0.34 \, \text{V}, \, E^\circ_{\text{Fe}^{2+}/\text{Fe}} = -0.44 \, \text{V} \, \text{and} \, F = 96,500 \, \text{C mol}^{-1} \right] \)