Question

Describe the following about halogen family elements:

Relative acid strength of hydrides.

Answer 1

1. The hydrides of halogens are HX (X = F, Cl, Br, I).
2. Acid strength increases as we move down the group: HF < HCl < HBr < HI.
3. HF is the weakest acid due to the strongest H–F bond and extensive hydrogen bonding.
4. HI is the strongest acid because of the weakest H–I bond, which breaks easily to release H⁺ ions.
5. The bond strength decreases down the group, making hydrides more acidic from F to I.

This order reflects bond dissociation energies and the ease of releasing H⁺ ions in water.