Identification of primary, secondary and tertiary amines — NEET & JEE Questions

Question 1 · difficulty L1 · recall

The carbylamine test is given by

• A. primary amines
• B. secondary amines
• C. tertiary amines
• D. all amines equally

Question 2 · difficulty L2 · understanding

Which reagent is used in the Hinsberg test to distinguish classes of amines?

• A. Benzenesulfonyl chloride in alkali
• B. Bromine water
• C. Tollens reagent
• D. Fehling solution

Question 3 · difficulty L2 · understanding

A primary amine reacts with benzenesulfonyl chloride in the Hinsberg test to form a sulfonamide that

• A. has an N-H proton and is soluble in alkali after deprotonation
• B. has no N-H bond and is insoluble in alkali
• C. does not react at all
• D. forms a permanent quaternary salt

Question 4 · difficulty L2 · understanding

In the Hinsberg test, a tertiary amine generally

• A. does not form a sulfonamide because it has no N-H bond
• B. forms an alkali-soluble sulfonamide
• C. forms an insoluble sulfonamide with an N-H bond
• D. gives the carbylamine reaction instead of any acid-base behaviour

Question 5 · difficulty L3 · application

An unknown amine gives a positive carbylamine test. What can be concluded?

• A. It is a primary amine
• B. It is definitely secondary
• C. It is definitely tertiary
• D. It contains no nitrogen

Question 6 · difficulty L3 · application

An amine reacts in the Hinsberg test to give a sulfonamide insoluble in alkali. Which class is most consistent?

• A. Primary
• B. Secondary
• C. Tertiary
• D. Quaternary ammonium salt

Question 7 · difficulty L3 · application

An unknown amine gives no carbylamine test and does not form a sulfonamide in the Hinsberg test, but dissolves in dilute acid. Which class is most consistent?

• A. Primary amine
• B. Secondary amine
• C. Tertiary amine
• D. Amide

Question 8 · difficulty L3 · application

Which amine would give a positive carbylamine test?

• A. $(CH_3)_3N$
• B. $(CH_3)_2NH$
• C. $C_6H_5NH_2$
• D. $CH_3CONH_2$

Question 9 · difficulty L4 · application

A sample forms an N-substituted benzenesulfonamide in the Hinsberg test, and that product dissolves in alkali. What can be concluded?

• A. The original amine was primary
• B. The original amine was secondary
• C. The original amine was tertiary
• D. The sample was an amide

Question 10 · difficulty L4 · application

A sample gives no carbylamine test. In the Hinsberg test it forms a sulfonamide that remains insoluble in aqueous alkali. Which class is indicated?

• A. Primary amine
• B. Secondary amine
• C. Tertiary amine
• D. Quaternary ammonium salt