Question

How will you distinguish between : 

(1) Ethylamine, diethyl amine and triethyl amine by using (i) nitrous acid (ii) Hinsberg’s reagent. 

(2) Diethyl amine and triethyl amine by using acetic anhydride.

Answer 1

Test	Ethyl amine	Diethyl amine	Triethyl amine
(1) (i) Using nitrous acid : Add nitrous acid to given amine	Forms ethyl alcohol and nitrogen gas.	Forms pale yellow oily N-Nitrosodiethylamine.	Forms water soluble triethyl ammonium nitrite salt
(ii) Hinsberg's reagent test : Mix given amine with small quantity of benzene sulphonyl chloride in the presence of aqueous KOH	A clear solution is obtained which on acidification gives insoluble N-alkyl benzene sulphonamide.	Gives insoluble compound which does not dissolve in acid.	No reaction.
(2) Using acetic anhydride : Given amine treated with acetic anhydride.	-	Forms a mono acetyl derivative,N,N-diethyl acetamide.	No reaction.