Question

The variation of boiling points of hydrogen halides
is in tha order `HF gt HI gt HBr gt HCl `. What
explains the higher boiling point of hydrogen fluoride ?
A. There is strong hydrogen bonding between HF molecules
B. The bond energy of HF molecules is greater
than in other hydrogen halides
C. The effect of nuclear shielding is much reduced
in fluorine which polarises the HF molecule
D. The electronegativity of flurine is much
higher than for other elements in the group .

Answer 1

Correct Answer - A
HF froms strong intermolecular hydrogen bonds
due to high elecrtonegatively of fluorine. Hence ,
the boiling point of HF is abnormally high. Boiling
points of other hydrogen halides gradually increase
from HCl to HI due to increase in the size of
halogen atom from Cl to I whihc results in the
increase of van Waal forces .