- The ethanoate can not form $H$ bonds, so it is more volatile than butanoic acid.
- Ethanoate and ethyl propanoate have the same polarity and the same molecular mass, therefore comparable volatilities.
- The butanamide forms more $H$ bonds than butanoic acid, it is less volatile.
- Butamine lacks the polar carbonyl $C = O$ group present in butanamide, in addition, its molecular mass is lower, it is more volatile.
