chapter 13 Amines Class 12 Chemistry Textbook Solution

4. Answer the following.

vii. Distinguish between ethylamine,  diethylamine and triethylamine by using Hinsberg’s reagent ?


(i) When a primary amine, such as ethylamine, undergoes a reaction with Hinsberg’s reagent (benzenesulfonyl chloride), it forms N-alkyl benzenesulfonamide. This compound is soluble in an aqueous solution of potassium hydroxide (KOH), resulting in the formation of a clear solution of potassium salt. Upon subsequent acidification, the N-alkyl benzenesulfonamide becomes insoluble.

Distinguish between ethylamine by using Hinsberg’s reagent

(ii) In the case of a secondary amine, like diethylamine, reaction with benzenesulfonyl chloride results in the formation of N,N-diethyl benzenesulfonylamide. This compound remains insoluble when placed in an aqueous KOH solution and does not dissolve when subjected to an acid environment.

Distinguish between diethylamine by using Hinsberg’s reagent

(iii) Tertiary amines, such as triethylamine, do not react with benzenesulfonyl chloride and thus remain insoluble in KOH. However, they can dissolve in dilute hydrochloric acid (HCl) to produce a clear solution due to the formation of an ammonium salt.

Distinguish between triethylamine by using Hinsberg’s reagent

13 Amines Class 12 Chemistry Textbook Solution page 297