Question

I ran across something saying that n-butanamine is miscible in water while butanol is only partially soluble. Is this correct? Can anyone offer an explanation? I would have guessed that the decreased polarity of the amine relative to the alcohol would have resulted in lower solubility for n-butanamine.

Answer 1

N-butanamine is miscible in water because it can form hydrogen bonds with water due to its NH2 group, whereas butanol is partially soluble due to its longer alkyl chain.

Step-by-step explanation:

You are correct that n-butanamine is miscible in water while butanol is only partially soluble. This can be explained by considering the types of hydrogen bonding each compound can form with water. N-butanamine has an NH2 group capable of forming hydrogen bonds with water molecules, making it miscible despite being less polar than butanol.

Concerning boiling points, butylamine would have a higher boiling point than butanol because of its ability to form stronger hydrogen bonds due to the presence of N-H bonds. Comparatively, trimethylamine would have a lower boiling point than propylamine, as it lacks hydrogen atoms on nitrogen and cannot form hydrogen bonds as effectively.