Why ethylamine is more basic than aniline ?

Explanation

In aniline, the lone pair of electrons on the N-atom are delocalisedover the benzene ring. As a result electron density on the nitrogen decreases. Whereas, in `CH_3NH_2`, +I-effect of `CH_3` increases ihe electron density of the N-atom. Therefore, aniline is a weaker base than methylamine and hence its `pK_b` is higher than that of methylamine.