Which of the following compounds does $NOT$ develop intermolecular hydrogen bonding?

Which of the following compounds contains a hydrogen bond?

Hydrogen bonding is present in:

Which of the following hydrogen bonds is the strongest in the vapour phase?

The hydrogen bond strength will be highest for

Observe the following substances: Ethanol,acetic acid,ethylamine,trimethylamine,salicylic acid,ethanal. In the above list,the number of substances with $H$-bonding is: