AIIMS2017Chemistry-Organic Chemistry

AIIMS 2017 Chemistry Nucleophilic Substitution Reactions Assertion Reason Question

Type: Assertion Reason-conceptual-Medium-Class 11

In the following questions a statement of Assertion (A) followed by a statement of Reason (R) is given. Choose the correct answer out of the following choice.

Assertion (A) Presence of nitro group facilitates nucleophilic substitution reactions in aryl halides.

Reason (R) The intermediate carbocation is stable due to presence of nitro group.

A

Both the statements are true and Reason is the correct explanation of Assertion.

B

Both the statements are true but Reason is not the correct explanation of Assertion.

C

Assertion is true but Reason is false.

D

Both the statements are false.

Correct Answer

Option C

Detailed Explanation

The assertion is true because the presence of a nitro group (−NO₂) on an aryl halide enhances the nucleophilicity of the aromatic ring, facilitating nucleophilic substitution reactions. However, the reason is false; the stability of the intermediate is not due to a carbocation but rather a Meisenheimer complex, where the nitro group stabilizes the negative charge developed during the reaction. Option A is incorrect because the reason does not correctly explain the assertion, while option B is also incorrect for the same reason. Option D is incorrect as the assertion is indeed true.

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