Question

The basic strength of alkylamines does not depend on which of the following?

(a) Number or alkyl groups

(b) Size of alkyl groups

(c) Physical state of the amine

(d) Presence of an aromatic ring

This question was posed to me in an interview for job.

The question is from Amines Chemical Reactions topic in division Amines of Chemistry – Class 12

Answer 1

Correct option is (d) Presence of an aromatic ring

Easy explanation: Since only basicity of alkylamines is in question the presence of aromatic ring is not considered. As the size and number of alkyl groups increases, the stability of ammonium ion (formed from the amine) increases due to dispersal of more positive charge by the +I effect of alkyl groups. The physical state, gaseous or aqueous, also determines the basicity as the hydration effect comes into play.