Question

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 delocalised π-electrons cloud is attracted more strongly by the nuclei of the carbon atoms than the electron cloud localised between two carbon atoms.
In the light of the above statements, choose the correct answer from the options given below

• A. Both (A) and (R) are true but (R) is not the true explanation of (A)
• B. (A) is false but (R) is true
• C. (A) is true but (R) is false
• D. Both (A) and (R) are true and (R) is the true explanation of (A)

Hint:

Resonance stabilization and delocalization of π electrons provide benzene with extra stability compared to hypothetical cyclohexatriene.

Answer 1

The Correct Option is D

Step 1: Understand the Concepts of Benzene and Cyclohexatriene

• Benzene (C_6H_6) is a well-known aromatic compound with a ring structure featuring alternating double bonds.
• Cyclohexatriene is a hypothetical compound that would have a similar structure to benzene but with localized double bonds, leading to a lack of overall conjugation.

Step 2: Analyze Assertion (A)

• Benzene is more stable than hypothetical cyclohexatriene due to its resonance stability. In benzene, the electrons are delocalized over the entire structure, creating a more stable, lower-energy configuration.

Step 3: Examine Reason (R)

• The reason provided states that the delocalised π-electron cloud in benzene is attracted more strongly by the nuclei of the carbon atoms compared to a localized electron cloud in a hypothetical compound like cyclohexatriene.
• This delocalization in benzene contributes to the stability as the π-electron cloud is constantly spreading out, thus lowering the potential energy of the system.

Conclusion: Determine the Correct Answer

• Both the assertion (A) and reason (R) are true.
• Furthermore, the reason given (R) correctly explains why benzene is more stable than the hypothetical cyclohexatriene.

Hence, the correct option is: Both (A) and (R) are true and (R) is the true explanation of (A).