The reaction of amines with mineral acids to form ammonium salts shows that these are basic in nature. Amines have an unshared pair of electrons on the nitrogen atoms due to which they behave as Lewis bases. The basicity of amines is related to their structure. The basic character of an amine depends upon the ease of formation of a cation by accepting a proton from the acid. The more stable the cation is relative to the amine, the more basic the amine.

Among the following amines, which one is most basic (in an aqueous solution)?

(C₂H₅)₂NH

In aqueous solution, secondary amine is most basic among aliphatic amines due to inductive effect, solvation effect, and steric hindrance of the alkyl group in aqueous medium. Hence, the basic strength order of the amines is:

(C₂H₅)₂NH > (C₂H₅)₂N > C₂H₅NH₂ > NH₃