Question

Arrange the following compounds in increasing order of their basic strength. Explain reason
$C_2{H}_{5}N{H}_2,N{H}_3,C_6{H}_{5}N{H}_2$

Answer 1

The increasing order of their basic strength is $C_6{H}_{5}N{H}_2<N{H}_3<C_2{H}_{5}N{H}_2$
In aniline, the lone pair of electrons on N atom is involved in resonance with benzene ring. Hence, it is less available for donation to suitable lewis acid. Hence, aniline is less basic than ammonia.
In ethyl amine, the ethyl group has +I effect. It increases electron density on N atom. Hence, N can easily donate its lone pair of electrons to suitable lewis acid. Hence, ethyl amine is more basic than ammonia.