Question

Which of the following observations can be explained on the basis of hydrogen bonding?
(i) $H-F$ has higher boiling point than other halogen acids.
(ii) $H_{2}O$ has highest boiling point among hydrides of group 16 elements.
(iii) $N{H}_3$ has lower boiling point than $P{H}_3$.

• A. (i), (ii) and (iii)
• B. (i) and (iii)
• C. (ii) and (iii)
• D. (i) and (ii)

Answer 1

Answer: (D)

(i) and (ii)

1.Due to the high electronegativity of flourine hydrogen bonds can be formed between HF molecules,hence H-F has high boiling point than other halogen.

2.Water has an anomalously high boiling point since its particles are bonded with each other by the hydrogen bonds in both its liquid as well as solid states.

3.$N{H}_3$ has a higher boiling point than $P{H}_3$ due to hydrogen bonding.

$N{H}_3$ has lower boiling point than $Bi{H}_3$ and $Sb{H}_3$

As in this case, the molecular weight is dominant over the hydrogen bonding.

So the correct option is $\left[D\right]$.