Give plausible explanation for each of the following:
(i) Why are amines less acidic than alcohols of comparable molecular masses?
(ii) Why do primary amines have higher boiling point than tertiary amines?
(iii) Why are aliphatic amines stronger bases than aromatic amines?

Explanation

i. The loss of a proton from an amine give an imide ion. While the loss of a proton from alcohol gives an alkoxide ion as shown below :
`underset("Amine")(R-NH_(2)) rarr underset("Imide ion")(R-overset(Theta)NH)+H^(o+)`
`R-O-H rarr R-O^(Theta) +H^(o+)`
Since `O` is more elecronegative than `N`, therefore, `(Roverset(Theta)O)`can accommodate the negative charge more easily than `Roverset(Theta)NH` can accommodate the negative charge. In other words, `RO^(Theta)` is more stable than `Roverset(Theta)NH`. Thus, alcohols are more acidic than amines. Conversely, amines are less acidic than alcohols.
ii. `1^(@)` amines form stronger intermolecular H-bonding between N atom of one and H atom of another molecule.
iii. Aliphatic amines are stronger bases due to `+I` effect of the alkyl group, leading to high `bar(e)` density on the N atom.