Explain the basicity of aromatic amines.

(N/A) Aromatic amines,such as aniline,are much less basic than ammonia and aliphatic amines. This is because the lone pair of electrons on the nitrogen atom is involved in resonance with the benzene ring.
In aniline,the lone pair of electrons on the nitrogen atom is delocalized over the benzene ring,as shown by the resonance structures $(I)$ to $(V)$. This delocalization makes the lone pair less available for donation to a proton $(H^{+})$.
Furthermore,when aniline accepts a proton to form an anilinium ion,the positive charge on the nitrogen atom cannot be delocalized over the benzene ring. The anilinium ion has only two resonance structures $(I)$ and $(II)$,which are less stable than the resonance-stabilized aniline molecule.
Due to these factors,aromatic amines are weaker bases than ammonia and aliphatic amines.