Chemistry - Nomenclature Question with Solution | TestHub

Question Explanation:

The question asks which given compounds are heterocyclic compound, meaning the ring contains carbon atoms as well as heteroatoms (O,N and S).

Concept :

This question is based on  Homocyclic Compounds, Heterocyclic Compounds, Hydrocarbons.

Solution:

A heterocyclic compound is a cyclic (ring) compound in which at least one atom in the ring is an element other than carbon, called a heteroatom.

Common heteroatoms are N, O, and S.

(I) Cyclohexane: Carbocyclic ring; only C and H → homocyclic hydrocarbon

(II) Piperidine: Ring contains N → heterocyclic

(III) Tetrahydrofuran: Ring contains O → heterocyclic

(IV) Cyclohexanol: Ring is carbocyclic, but –OH introduces O → not a hydrocarbon

(V) Aniline: Benzene ring is carbocyclic, but –NH₂ introduces N → not a hydrocarbon

(VI) 3-Methylpiperidine: Ring contains N → heterocyclic

(VII) Methylcyclohexane: Carbocyclic ring; only C and H → homocyclic hydrocarbon

(VIII) 1,3,5-Trimethylcyclohexane: Carbocyclic ring; only C and H → homocyclic hydrocarbon (II), (III) and (VI) are heterocyclic compounds.