Question

N – Butylamine (I) Diethylamine (II) and N, N

dimethylethyl amine (III) have the same molar mass. The increasing order of their boiling point is.

• A. III < II < I
• B. I < II < III
• C. II < III < I
• D. II < I < III

Answer 1

Answer: (A)

III < II < I

Answer 2

:

Primary amines have two hydrogen atoms available for hydrogen bond formation, while $2º$ amines have only one hydrogen atom for hydrogen bond formation. $3º$ amines do not have intermolecular association due to absence of hydrogen atom.

Thus, order of boiling point of isomeric amine is as follows $3º < 2º < 1º$ or III < II < I