Chemistry - Carboxylic acid and their Derivatives Question with Solution | TestHub
Consider the following compounds (A), (B), (C) and (D) :-
The order of decreasing reactivity towards hydrolysis by aqueous NaOH is :-
Options:
Answer:
Solution:
Question Explanation:
The question compares the reactivity of substituted amides toward base-catalyzed hydrolysis .
Concept:
This problem is based on the amide hydrolysis mechanism and the effect of substituents on the electrophilicity of the carbonyl carbon.
Solution:
Base hydrolysis of an amide starts with nucleophilic attack of OH- on the carbonyl carbon . Therefore, the more electrophilic the carbonyl carbon, the faster the reaction.
Electron-withdrawing groups (–NO2 ) on the aromatic ring increase the electrophilicity of the 2 carbonyl carbon and enhance the rate of hydrolysis.
A para-NO₂ group exerts the strongest −I and −M effects → maximum activation.
A meta-NO₂ group shows only −I effect → less activation than para.
Unsubstituted amide shows moderate reactivity.
Aliphatic/cycloalkyl groups donate electron density (+I effect), decreasing electrophilicity and slowing hydrolysis.
