When we move from HF to HCl , the boiling point sharply but on moving further to HBr and HI the boiling point increases . Why ? Or Out of HF, HCl , HBr and HI which has boiling point and why ?

Options

A. `HF gt HCl gt HBr gt HI`
B. `HF gt HI gt HBr gt HCl`
C. `HI gt HBr gt HCl gt HF`
D. `HCl gt HF gt HBr gt HI`

Answer

B

Explanation

`HF gt HI gt HBr gt HCl`
HF is hydrogen bonded, thus has highest boiling point, and it is liquid at or below 19ºC. The remaining hydrogen halides are gaseous and their boiling points depend on the vander Waal.s forces. Larger the size (or molecular mass), greater is the vander Waals forces, hence higher is the boiling point. Thus the order is
`HI gt HBr gt HCl " and overall " HF gt HI gt HBr gt HCl`.