What is the correct order of basic strength of the following

what-is-the-correct-order-of-basic-strength-of-the-following

What is the correct order of basic strength of the following ethyl substituted amines in aqueous solution? (R=ethyl group)

A. RNH2 > R2NH > R3N

B. R2NH > R3N > RNH2

C. R3N > R2NH > RNH2

D. R2NH > RNH2 > R3N

I had been asked this question in an international level competition.

This interesting question is from Amines Chemical Reactions topic in division Amines of Chemistry – Class 12

The correct choice is B. R2NH > R3N > RNH2

The explanation is: There is a subtle interplay of inductive effect, solvation effect and stearic hinderance of alkyl groups to determine the order of basicity of alkylamines in aqueous solutions. For ethyl substituted amines, it is 2°>3°>1°