Basicity Of Organic Compounds

Basicity of an amine reflects how readily the lone pair on nitrogen is donated to a proton, which increases when the electron density on nitrogen is raised. In methylamine, the attached methyl group is electron-releasing and exerts a +I effect, pushing electron density toward nitrogen and making its lone pair more available for protonation than in ammonia, where nitrogen bears only hydrogens. Hence methylamine is the stronger base. The option claiming the methyl group withdraws electron density is wrong because alkyl groups are electron-donating, not withdrawing. The claim that methylamine has no lone pair is false; nitrogen retains its characteristic lone pair, which is the very source of basicity. The statement that nitrogen is sp hybridised is incorrect, since amine nitrogen is sp^3 with a lone pair in an sp^3 orbital. This explanation matches the NCERT discussion of the inductive effect on basicity in the gas phase and in dilute conditions where only electronic donation is considered. In aqueous solution the picture is complicated by solvation of the protonated cation, which is why the experimental order of amine basicity in water is not strictly monotonic; the question deliberately restricts attention to electron availability. Plausibility check: a more electron-rich nitrogen holds a proton more strongly, so increased electron donation must raise basicity, confirming methylamine as the stronger base.