Although electron gain enthalpy of fluorine is less negative as compared to chlorine, fluorine is a stronger oxidising agent than chlorine. Why ?

Although electron gain enthalpy of fluorine is less negative as compar

1.	Although electron gain enthalpy of fluorine is less negative as compared to chlorine, fluorine is a stronger oxidising agent than chlorine. Why ?
Answer» SOLUTION :The OXIDISING capability of a substance can be determined by its electrode potential. Higher the electrode potential, stronger is the oxidising agent. The electrode potential, in turn, depends upon the following three factors : (i) Bond dissociation enthalpy (ii) Electron gain ENETHALPY and, (iii) Hydration energy. Although electron gain enthalpy of flrorine is less negative than that of chlorine but (a) enthalpy of disociation of F-F bond (158.8 kJ `mol^(-1)`) is much lower than that of CI-CI bond (242.6 kJ `mol^(-1)`), and (b) hydration enthalpy of `F^(-)` ion (515 kJ `mol^(-1)`) is much higher than that of `CI^(-)` ion (381 kJ `mol^(-1)`). Because of these two reasons, electrode potential of `F_(2)`(+ 2.87 V) is much higher than that of `CI_(2)` (+ 1.36 V) and hence `F_(2)` is a stronger oxidising agent than `Cl_(2)`