The correct order of boiling point of ethyl dimethyl amine , n-butyl amine and diethyl amine is

Question

The correct order of boiling point of ethyl dimethyl amine , n-butyl amine and diethyl amine is (A)  B>C>A  (B)  B>A>C  (C)  A>B>C  (D)  C>B>A

Tardigrade Admin · Accepted Answer

Among 1° ,2° and 3° amines, the primary amine has the maximum strength to form the H-bond. The dipole-dipole attraction force also works between these molecules, hence the boiling point of primary amine is maximum. Between 2° and 3° amines, the tertiary amines does not form H-bond while secondary amine has some strength to form H-bond. Hence, the order of boiling point is as; underset beginsmallmatrix n-butyl text amine 1° amine (B) endsmallmatrix mathopC4H9NH2 > underset beginsmallmatrix diethyl text amine 2° amine (C) endsmallmatrix mathop(C2H5)2NH > underset beginsmallmatrix ethyl text diethyl text amine 3° amine (A) endsmallmatrix mathopC2H5N(CH3)2

Q. The correct order of boiling point of ethyl dimethyl amine , n-butyl amine and diethyl amine is

$B > C > A$

$B > A > C$

$A > B > C$

$C > B > A$