Question

Resonance is not exhibited by................…?

• A. Phenol
• B. Aniline
• C. Nitrobenzene
• D. Cyclohexane

Answer 1

The correct option is D

Cyclohexane

Explanation for the correct option:

Option(D):Cyclohexane

• Resonance is generally known to be observed in the compounds having alternate single and multiple bonds i.e conjugated compounds.
• The actual structure of any given compound is known to be the resonance hybrid of various possible alternate structures which are known as resonating structures or canonical structures.
• Hence, to show resonance effect the compounds must contain the delocalization of pi electrons or unshared electrons without shifting any atom.
• From the structures of Cyclohexane, we can conclude that it does not have any delocalized conjugated pi-electron system, hence it does not show any resonance.

The explanation for the incorrect option:

Option(A):Phenol

• Phenol is generally known to exhibit Resonance, as it has the delocalized conjugated pi-electron system, which can be shown as:

• Hence, it shows resonance.

Option(B):Aniline

• Resonance can be exhibited by Aniline, as it is a conjugated molecule, which can be shown as:

• Hence, it shows resonance.

Option(C):Nitrobenzene

• Nitrobenzene is generally known to exhibit Resonance, as it has the delocalized conjugated pi-electron system, which can be shown as:

• Hence, it shows resonance.

Hence, Resonance is not exhibited by Cyclohexane and the correct option is (D).