NEETChemistryHaloalkanes and Haloarenes
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): Chlorobenzene is much less reactive than cyclohexyl chloride towards nucleophilic substitution reactions. Reason (R): In chlorobenzene, the C-Cl bond acquires a partial double bond character due to resonance, and the phenyl cation formed is highly unstable. In the light of the above statements, cho
Options
- ABoth Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A)
- BBoth Assertion (A) and Reason (R) are correct but Reason (R) is not the correct explanation of Assertion (A)
- CAssertion (A) is correct but Reason (R) is not correct
- DAssertion (A) is not correct but Reason (R) is correct
Correct answer
A. Both Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A)
Step-by-step solution
Assertion (A) is correct because aryl halides like chlorobenzene are extremely unreactive towards nucleophilic substitution compared to alkyl halides like cyclohexyl chloride. Reason (R) is also correct and explains the assertion. The unreactivity of chlorobenzene is primarily due to resonance, which imparts a partial double bond character to the C-Cl bond, making it difficult to break. Furthermore, for an S _ N 1 mechanism, the intermediate phenyl cation formed is highly unstable because the positive charge is on