The variation of the boiling point of the hydrogen halides is in the order `HFgtHIgtHHHHHBrgtHCI`

Options

A. the bond energy of `HF` molecules is greater than in other hydrogen halides
B. the effect of nuclear shielding is much reduced in flurorine which polarisses the `HF`molecules
C. The electronegativity of fluorine is much higher than for other element in the group
D. There is strong hydrogen bonding between `HF` molecules

Answer

4

Explanation

Amongest hydrogen halides ,the boiling point of `HF` is highest i.e,` 293K` due to extensive intermolecular hydrogen bonidng. The other hydrogen halides do not show hydrogen bonding because of the lower electronegativity of the halogens in them the boiling point of `HCl, HBr` and `HI` are much lower than that of `HF`.
Lowever as we move form `HCl` ot `HI` their boiling points show a regular increase due to a corresponding increase in the magnitude of van der Waal's forces (of attraction) on account of increase of molecular mass and increase of size of the halogen Similar trend is observed for melting points