Question

Fluorine has lower electron affinity than chlorine and yet it is a stronger oxidising agent than chlorine. Explain.

Give appropriate reason for the following observation:

Fluorine is a stronger oxidising agent than chlorine, though fluorine has lower electron affinity than chlorine.

Answer 1

1. Fluorine has lower electron affinity than chlorine due to its very small atomic size causing high electron-electron repulsion, which makes it harder to add an extra electron smoothly. Chlorine, being larger, experiences less repulsion, so it releases more energy when gaining an electron.
2. Despite this, fluorine is a stronger oxidizing agent because it has the highest electronegativity, meaning it strongly attracts electrons from other substances.
3. Also, fluorine’s small size and high effective nuclear charge enhance its ability to pull electrons from other species, giving it stronger oxidizing power than chlorine.

Therefore, fluorine oxidizes other elements more readily even though its electron affinity is lower than chlorine’s.