Match List-I (common name) with List-II (IUPAC name) for the four amines of molecular formula C3H9N.
| List-I (Common name) | List-II (IUPAC name) |
|---|---|
| (A) n-Propylamine | (I) N-Methylethanamine |
| (B) Isopropylamine | (II) Propan-2-amine |
| (C) Ethylmethylamine | (III) N,N-Dimethylmethanamine |
| (D) Trimethylamine | (IV) Propan-1-amine |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → A-IV, B-II, C-I, D-III
In the IUPAC system a primary amine is named as an alkanamine, with a number for the carbon carrying –NH2. In secondary and tertiary amines the longest alkyl group gives the parent name, and the other groups on nitrogen get the locant N.
(A) n-Propylamine, \( \ce{CH3CH2CH2NH2} \) — This matches (IV) Propan-1-amine. The –NH2 group is on carbon 1 of the propane chain.
(B) Isopropylamine, \( \ce{CH3CH(NH2)CH3} \) — This matches (II) Propan-2-amine. The –NH2 group is on the middle carbon, carbon 2.
(C) Ethylmethylamine, \( \ce{CH3NHCH2CH3} \) — This matches (I) N-Methylethanamine. Ethyl is the larger group, so the parent is ethanamine; the methyl group sits on nitrogen.
(D) Trimethylamine, \( \ce{(CH3)3N} \) — This matches (III) N,N-Dimethylmethanamine. One methyl group gives methanamine; the other two are on nitrogen, so N,N-dimethyl.
NCERT (2026-27 edition):
9.3 Nomenclature – “…In IUPAC system, primary amines are named as alkanamines. … To name secondary and tertiary amines, we use locant N to designate substituent attached to a nitrogen atom. For example, CH3NHCH2CH3 is named as N-methylethanamine …”
Table 9.1: Nomenclature of Some Alkylamines and Arylamines
