Question

Give appropriate reason for the following observation:

Despite its lower electron affinity, fluorine is a stronger oxidising agent than chlorine.

Answer 1

1. A fluorine atom is very small, causing high electron density, which repels incoming electrons and reduces the energy released when gaining an electron. Hence, its electron affinity is lower than chlorine’s.
2. Fluorine is the most electronegative element, which makes it very effective at attracting electrons from other substances.
3. The oxidising power depends not only on electron affinity but also on electronegativity and bond strength.
4. Fluorine’s \[\ce{F - F}\] bond is weaker than \[\ce{Cl - Cl}\] bond, so it can more easily gain electrons and oxidise other substances.
5. Therefore, fluorine can oxidise chloride ions and other halide ions, displacing them from solutions, showing stronger oxidising ability than chlorine.