Which of the following organic compounds show Carbylamine test?
A. Ethanamine
B. N-Ethylethanamine
C. N,N-Dimethylethanamine
D. Aniline
E. N-Methyl aniline
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → A, D only
In the carbylamine reaction (isocyanide test), an amine is heated with chloroform and ethanolic KOH. Only primary amines, aliphatic or aromatic, react; they form isocyanides (carbylamines), which have a very unpleasant smell:
\( \displaystyle \ce{R-NH2 + CHCl3 + 3KOH} \xrightarrow{\text{heat}} \ce{R-NC + 3KCl + 3H2O} \)
The reaction needs the two hydrogens of an –NH2 group; secondary and tertiary amines do not have them and give no test.
A. Ethanamine — Correct. \( \ce{CH3CH2NH2} \) is a primary aliphatic amine; it gives ethyl isocyanide, \( \ce{C2H5NC} \).
B. N-Ethylethanamine — Incorrect. \( \ce{(C2H5)2NH} \) is a secondary amine.
C. N,N-Dimethylethanamine — Incorrect. \( \ce{(CH3)2NC2H5} \) is a tertiary amine.
D. Aniline — Correct. \( \ce{C6H5NH2} \) is a primary aromatic amine; it gives phenyl isocyanide, \( \ce{C6H5NC} \).
E. N-Methyl aniline — Incorrect. \( \ce{C6H5NHCH3} \) is a secondary amine.
NCERT (2026-27 edition):
Carbylamine Reaction
