34.2.3—Basicities of aq. ammonia, ethylamine

In water the usual basicity order is ethylamine > ammonia > phenylamine. An ethyl group donates electron density towards nitrogen, while in phenylamine the lone pair is delocalised into the benzene ring.

A more available lone pair accepts H⁺ more readily. Solvation and the aqueous environment matter, so use the syllabus order rather than a gas-phase shortcut.

Ethylamine produces a higher equilibrium concentration of OH⁻ than ammonia at comparable conditions; phenylamine’s ring delocalisation makes proton acceptance less favourable.

Phenylamine is still basic. Delocalisation reduces its basicity; it does not remove the nitrogen lone pair.