MHT CET202520 Apr 2025Evening ShiftChemistryp Block Elements (Group 15, 16, 17 & 18)Actual
Identify the correct decreasing order of boiling point for hydrides of halogens.
Options
- AHF > HCl > HBr > HI
- BHI > HBr > HCl > HF
- CHF > HI > HBr > HCl
- DHI > HF > HBr > HCl
Correct answer
C. HF > HI > HBr > HCl
Step-by-step solution
The boiling points of hydrogen halides are determined by their intermolecular forces. Hydrogen fluoride (HF) exhibits strong hydrogen bonding due to fluorine's high electronegativity and small size, resulting in a significantly elevated boiling point compared to other hydrogen halides. Hydrogen chloride (HCl), hydrogen bromide (HBr), and hydrogen iodide (HI) lack hydrogen bonding capabilities. Their boiling points depend on London dispersion forces, which strengthen with increasing molecular size and electron count