MCQ
Among the following amines, which one has the highest $pK_b$ value in aqueous solution?
- AMethanamine
- B$N, N -$ dimethylaniline
- CEthanamine
- ✓Benzenamine
✓
Answer
Correct option: D.
Benzenamine
$+$Inductive effct increases the electron density on nitrogen thus makes it more basic while $+R$ effect involves the lone pair of $N$ in conjugation thereby reduces its basicity.
Therefore aniline are less basic than alkyl amines and secondary aniline are more basic than aniline.
Highest $pK_b$ means least basic nature
Therefore aniline are less basic than alkyl amines and secondary aniline are more basic than aniline.
Highest $pK_b$ means least basic nature
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