Question

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

Answer 1

The electron gain enthalpy of chlorine is more negative than that of fluorine. However, the bond dissociation energy of fluorine is much lesser than that of chlorine. In addition, its small size, the hydration energy of fluorine is much higher than that of chlorine. So, the latter two factors more than compensate for the less negative electron gain enthalpy of fluorine. Thus, fluorine is a much stronger oxidizing agent than chlorine