Question

\( E^0 \) value of Cu\(^{2+}\)/Cu is \( +0.34 \) V.

Hint:

- High atomization enthalpy and low hydration enthalpy make Cu\(^{2+} \rightarrow\) Cu less favorable, giving a positive \( E^0 \) value.

Answer 1

The high atomization enthalpy (\( \Delta H^0_{\text{atom}} \)) and low hydration enthalpy (\( \Delta H^0_{\text{hydr}} \)) of copper make its standard reduction potential (\( E^0 \)) positive.
Explanation of \( E^0 \) Value - The electrode potential (\( E^0 \)) depends on: - Atomization enthalpy (\( \Delta H^0_{\text{atom}} \)): The energy required to convert solid Cu to Cu\(^{2+}\) is high. - Hydration enthalpy (\( \Delta H^0_{\text{hydr}} \)): Cu\(^{2+}\) has low hydration energy, making it less stable in aqueous solution. Effect on \( E^0 \) Value - Due to low hydration enthalpy, the reduction of Cu\(^{2+}\) to Cu is not highly favored. - Hence, Cu\(^{2+}/\)Cu has a positive \( E^0 \) value of \( +0.34 \) V, indicating that Cu is less reactive than expected.