Account for the following
(i)Primary amines `(R-NH_(2))` have higher boiling point than tertiary amines `(R_(3)N)`
(ii) Aniline does not undergo friedel - crafts reaction
(iii) `(CH_(3))_(2)` NH is more basic than `(CH_(3))_(3)N` in an aquaous solution

Explanation

The basicity of `(CH_(3))_(2)NH and (CH_(3))_(3)N` mainly depends upon the stability of the ammonium cation formed when each one of them accepts a proton. Since the ammonium cation derived from `(CH_(3))_(2)NH` is stabilized by H-bonding with only one H-atom, therefore, `(CH_(3))_(2)NH` is more basic than `(CH_(3))_(3)N`.

(ii) The boiling points of amines depnds upon the degree of association due to H-bonding which, in turn, depends upon the number of H-atoms on the N-atom. since `1^(@)` amines have two H-atoms linked to N-atom while `3^(@)` amines have no H-atom linked to N-atom, therefore, `1^@` amines exist as associated

Molecules (as shown above) while `3^(@)` amines exist as individual molecules. to break these H-bonds, large amount of nergy is needed. therefore, `1^(@)` amines have higher boiling point than `3^(@)` amines.