Q1. [1]
Consider the structures of the three cyclic carbon compounds A, B and C given below and select the correct option from the following :
- (a) A and C are isomers of hexane and B is benzene.
- (b) A is an isomer of hexane, B is benzene and C is an isomer of hexene.
- (c) A is a saturated cyclic hydrocarbon and B and C are unsaturated cyclic hydrocarbons.
- (d) A is cyclohexane and B and C are the isomers of benzene.
Previously asked in CBSE board exam
2023 31/1/1 Q7
Generated by claude-sonnet-4-6 · 2026-06-15 06:50 · grounding rag
Model Answer
The correct option is (c): A is a saturated cyclic hydrocarbon (cyclohexane, C₆H₁₂) and B and C are unsaturated cyclic hydrocarbons (both contain double bonds).
Explanation
- A = cyclohexane (C₆H₁₂) — fully saturated ring; it is an isomer of hexene (not hexane, as hexane is C₆H₁₄ with a different formula).
- B = benzene (C₆H₆) — unsaturated, with alternating double bonds.
- C — also an unsaturated cyclic compound with double bond(s); it is not an isomer of benzene (different formula/structure).
- Option (a) and (b) are wrong because cyclohexane is NOT an isomer of hexane (C₆H₁₄ ≠ C₆H₁₂). Option (d) is wrong because C is not an isomer of benzene. Only option (c) correctly classifies all three on the basis of saturation.
If a question refers to an image, map, graph or diagram that is not shown here, open the Study Guide single page app, go to
Library and find the actual CBSE question paper. The original papers are also available on the CBSE website:
cbse.gov.in.