Hydrogen bonds are formed in many compounds e.g. `H_(2)O`, HF, `NH_(3)`. The boiling point of such compounds depends to a extent on the strength of hydrogen bond and the number of hydrogen bonds. The correct decreasing order of the boiling points above compounds is

Options

A. `HF gt H_(2)O gt NH_(3)`
B. `H_(2)O gt HF gt NH_(3)`
C. `NH_(3) gt HF gt H_(2)O`
D. `NH_(3) gt H_(2)O gt HF`

Answer

B

Explanation

b) Strength of H-bond is in the order H....F `gtH.....OgtH.....N`
But each `H_(2)O` molecule is linked to four other `H_(2)O` molecules through H-bonds whereas each HF molecules is linked only to two other HF molecules.
Hence, b.p of `H_(2)O gt b.p` of `HFgtb.p` of `NH_(3)`