Question

The decreasing order of basic strength in aqueous solution of amines is

• A. Dimethylamine \(>\) Methylamine \(>\) Trimethylamine \(>\) Ammonia
• B. Methylamine \(>\) Dimethylamine \(>\) Trimethylamine \(>\) Ammonia
• C. Trimethylamine \(>\) Dimethylamine \(>\) Methylamine \(>\) Ammonia
• D. Ammonia \(>\) Trimethylamine \(>\) Dimethylamine \(>\) Methylamine
• E. Ammonia \(>\) Dimethylamine \(>\) Trimethylamine \(>\) Methylamine

Hint:

The basic strength of amines decreases as the number of alkyl groups increases because the electron-donating effect of alkyl groups makes nitrogen less available for protonation.

Answer 1

The Correct Option is A

In aqueous solution, basicity depends on the availability of the lone pair on the nitrogen atom for protonation. Dimethylamine is the strongest base, followed by methylamine, trimethylamine, and ammonia. 
Thus, the correct order of basicity is (A).