Question

Which among the following compounds does not exhibit resonance?

• A. Cyclohexane
• B. Phenol
• C. Aniline
• D. Nitro ethane

Hint:

Molecules with delocalized electrons, such as those with conjugated systems, typically exhibit resonance, while simple molecules like cyclohexane do not.

Answer 1

The Correct Option is A

Step 1: Understanding resonance.
Resonance occurs when a molecule can be represented by two or more valid Lewis structures that differ only in the placement of electrons. Cyclohexane does not exhibit resonance as it has a simple, single structure with no delocalized electrons.
Step 2: Analyzing the options.
(A) Cyclohexane: Correct — Cyclohexane does not exhibit resonance because its structure is a stable, single form with no delocalized electrons.
(B) Phenol: Incorrect. Phenol exhibits resonance due to the delocalization of the lone pair of electrons on the oxygen atom.
(C) Aniline: Incorrect. Aniline exhibits resonance with the lone pair of electrons on the nitrogen atom delocalizing into the benzene ring.
(D) Nitro ethane: Incorrect. Nitro ethane exhibits resonance due to the delocalization of electrons in the nitro group.
Step 3: Conclusion.
The correct answer is (A) Cyclohexane, as it does not exhibit resonance.