Question

Which of the following hydrogen bonds are strongest in the vapour phase?
(A) $HF.....HF$
(B) $HF.....HCl$
(C) $HCl.....HCl$
(D) $HF.....HI$

Answer 1

Hint: Hydrogen bond is strongest in the above options before which we must know what hydrogen bonding is. The interaction known as hydrogen bonding, which involves a hydrogen atom sandwiched between two other atoms with a high affinity for electrons, is stronger than van der Waals forces but weaker than ionic or covalent bonds.
Complete Step by step solution:
Only some molecules containing N, O, or F can form hydrogen bonds. It is not nearly electronegative enough and is far too large. Polar covalent bonds make up the HCl bond. The ionic characteristics of HCl are true, and water completely dissolves it. But because of its hydrogen connections with water, HF does not completely dissociate in solution.
Because of this, HF has a strong H-bond and resides in the vapour phase as a polymer.
Therefore, the correct answer as from the above conclusion is $HF.....HF$ .

Hence, the correct option is (A)

Note: Vapour phase involves passing a vapour sample through a stationary phase, such as silica particles, and then desorbing it with a desorbent or carrier gas to convert it from a vapour to a solid phase. This is known as the vapour phase, and the word is frequently used in inquiries.