Physical properties of Aliphatic Amines:
(i) Physical state, odour: C1 ≈ C3 amines are colorless gas in normal temperature, higher amines are liquid or solid. Aliphatic amines have a characteristic fishy odour.
(ii) Melting point & Boiling Point: M.P & B.P rise with the increase of molecular mass. But amines have lower boiling point. Than corresponding alcohols e.g. boiling point of methyl amine is -7.50C & boiling point of methanol is 64.50 C.
(iii) Solubility: They are water soluble due to formation of H-bond. But solubility decreases with increase of molecular mass. Higher aliphatic amines arc soluble in organic solvents like benzene, ether & chloroform etc.