(a) Give one chemical test to distinguish between the following pairs of compounds : (i) Methylamine and dimethylamine (ii) Aniline and benzylamine. (b) Write the structures of different isomers corresponding to the molecular formula C_(3)H_(9)N, which will liberate nitrogen gas on treatment with nitrous acid.

(a) Give one chemical test to distinguish between the following pairs

1.	(a) Give one chemical test to distinguish between the following pairs of compounds : (i) Methylamine and dimethylamine (ii) Aniline and benzylamine. (b) Write the structures of different isomers corresponding to the molecular formula C_(3)H_(9)N, which will liberate nitrogen gas on treatment with nitrous acid.
Answer» Solution :(a) (i) Methylamine and dimethylamine : Methylamine reacts with nitrous acid to form ALCOHOL with the liberation of `N_(2)`. Dimethylamine does not give this test. `""CH_(3)NH_(2)+HNO_(2) overset(NaNO_(2)+HCl)(rarr) underset("Methanol")(CH_(3)OH)+N_(2)+HCl` (ii) Aniline and benzylamine : Aniline reacts with nitrous acid at 273-278 K to form benzene DIAZONIUM chloride which reacts further with phenol for form an ORANGE dye. Benzylamine does not give this test. (b) Structures of isomers : `""underset("n-Propyl amine")(CH_(3)-CH_(2)CH_(2)NH_(2))""underset("ISOPROPYL amine")(CH_(3)-underset(underset(CH_(3))(\|))(CH)-NH_(2))`