Given below are two statements, one is labelled as Assertion A and the other is labelled as Reason R. Assertion A: Benzene is more stable than hypothetical cyclohexatriene.
Reason R : The delocalized electron cloud is attracted more strongly by nuclei of carbon atoms. In the light of the above statements, choose the correct answer from the options given below:
Reason R : The delocalized electron cloud is attracted more strongly by nuclei of carbon atoms. In the light of the above statements, choose the correct answer from the options given below:
- (A)A is true but R is false.
- (B) is false but is true.
- (C)Both A and R are correct and R is the correct explanation of A .✓ Correct
- (D)Both A and R are correct but R is NOT the correct explanation of A.
Answer: (C)
Solution
Benzene does possess greater stability than a hypothetical cyclohexatriene of three isolated double bonds, a stability measured as its resonance energy, so the assertion holds. The six electrons are not confined to alternate bonds but spread into a continuous cloud above and below the ring, and this delocalised cloud is drawn simultaneously towards all the carbon nuclei, lowering the energy of the molecule. That attraction of the delocalised electrons by the nuclei is exactly the origin of the added stability, so the reason is true and is the correct explanation of the assertion.
JEE Main · 2023 · 24 Jan 2023 · Shift 2 · Single correct option