Which is more acidic (or basic), aniline or ammonia?

Explanation

Due to delocalization of the lone pair of electrons of the N-atom of aniline over the benzene ring, aniline is less basic than ammonia.
Conversely, loss of a proton from aniline gives ion (I) while than from `NH_(3)` gives ion (II).
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Since ion (I) is stabilized by resonance while ion (II) is not. therefore, aniline is more acidic than ammonia.