Predict giving reasons, the order of basicity of the following compounds in (i) gaseous phase and in (ii) aqueous solutions (CH_(3))_(3)N, (CH_(3))_(2)NH, CH_(3)NH_(2), NH_(3).

Predict giving reasons, the order of basicity of the following compoun

1.	Predict giving reasons, the order of basicity of the following compounds in (i) gaseous phase and in (ii) aqueous solutions (CH_(3))_(3)N, (CH_(3))_(2)NH, CH_(3)NH_(2), NH_(3).
Answer» Solution :(i) In gaseous phase : The order of basicity is : `""(CH_(3))_(3)N gt (CH_(3))_(2)NH gt CH_(3)NH_(2) gt NH_(3)` This is explained on the INDUCTIVE effect (+I) of the alkyl groups. (ii) In AQUEOUS phase : The order of basicity in aqueous solution is : `""(CH_(3))_(2)NH gt CH_(3)NH_(2) gt (CH_(3))_(3)N gt NH_(3)` Due to steric hindrance, the lone pair of electrons on N in `(CH_(3))_(3)N` is not readily availlable. Therefore, `(CH_(3))_(3)N` is LESS basic than `(CH_(3))_(2)NH" and "CH_(3)NH_(2)`. The inductive effect, solvation effect, H-bonding and steric hindrance together decide the basicity of amines in aqueous solutions.