Question

The correct decreasing order of boiling points of hydrogen halides is:

• A. \(HF > HCl > HBr > HI\)
• B. \(HI > HBr > HCl > HF\)
• C. \(HF > HI > HBr > HCl\)
• D. \(HI > HF > HBr > HCl\)

Hint:

Boiling points of hydrogen halides depend on hydrogen bonding and molecular weight.

Answer 1

The Correct Option is C

Hydrogen fluoride (HF) has the highest boiling point among hydrogen halides due to strong hydrogen bonding. The remaining hydrogen halides (HCl, HBr, HI) exhibit increasing boiling points with increasing molecular weight and van der Waals forces. Thus, the correct order is:

\(HF > HI > HBr > HCl\)

This is because HF forms strong intermolecular hydrogen bonds, while other halides rely on weaker van der Waals interactions. HI, being the heaviest, has stronger van der Waals forces than HBr and HCl.