Decreasing order of basicity for the following compounds:
(A) Ethylamine
(B) Diethylamine
(C) Ammonia
(D) Benzenamine
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → (B), (A), (C), (D)
Basicity depends on availability of lone pair on nitrogen.
Electron donating alkyl groups increase basicity. Resonance delocalization decreases basicity.
Detailed Explanation
Option A: Ethylamine
Primary amine with one alkyl group.
Shows +I effect but less than diethylamine.
Hence second.
Option B: Diethylamine
It is a secondary amine.
Two ethyl groups donate electron density via +I effect.
This increases availability of lone pair.
Hence most basic.
Option C: Ammonia
No alkyl group.
No +I effect.
So less basic than alkyl amines.
Option D: Benzenamine
Lone pair is delocalized into benzene ring via resonance.
Thus less available for protonation.
Hence least basic.
The decreasing order of basicity is:
secondary amine > primary amine > no alkyl groups > aniline
So
Diethylamine > Ethylamine > Ammonia > Benzenamine