AIIMS2018Chemistry-Organic Chemistry

AIIMS 2018 Chemistry Basicity of Amines MCQ Question

Type: MCQ-conceptual-Medium-Class 11

Assertion : N,N–Diethylethanamine is more basic then N,N-Dimethylmethanamine

Reason : +I effect of ethyl is more then methyl

A

If both assertion and reason are true and reason is the correct explanation of assertion.

B

If both assertion and reason are true but reason is not the correct explanation of assertion.

C

If assertion is true but reason is false.

D

If both assertion and reason are false.

Correct Answer

Option A

Detailed Explanation

N,N-Diethylethanamine is more basic than N,N-Dimethylmethanamine due to the stronger electron-donating inductive effect of the ethyl groups compared to the methyl groups. Ethyl groups (C₂H₅) are larger and provide a greater electron density through hyperconjugation, enhancing the availability of the lone pair on the nitrogen atom for protonation. In contrast, methyl groups (CH₃) exert a weaker inductive effect, making N,N-Dimethylmethanamine less basic. The other options are not applicable as they do not provide relevant information or alternative explanations regarding the basicity of these amines.

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