Question

Assertion (A): p-Nitroaniline is a weaker base than p-toluidine. Reason (R): The electron-withdrawing effect of \(-NO_2\) group in p-nitroaniline makes it a weaker base.

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

Hint:

Electron-withdrawing groups decrease basicity, while electron-donating groups increase basicity in aromatic amines.

Answer 1

The Correct Option is A

- p-Nitroaniline is weaker than p-toluidine because the \(-NO_2\) group is electron-withdrawing (-M and -I effect), decreasing the electron density on the nitrogen of the amine, reducing its basicity. - In contrast, the \(-CH_3\) group in p-toluidine is electron-donating (+I effect), increasing electron density on nitrogen and enhancing basicity. - Since both the assertion and reason are correct, and Reason (R) explains Assertion (A), option (A) is correct.