Question

Which of the following should be most volatile?
(I) $CH_3CH_2CH_2NH_2$
(II) $(CH_3)_3N$

(IV) $CH_3CH_2CH_3$

• A. II
• B. IV
• C. I
• D. III

Answer 1

Answer: (B)

The order of boiling points of isomeric amines is $1^°$ amines $>\, 2^°$ amines $> \,3^°$ amines.
Because of absence of H-atom available for hydrogen bonding, $3^°$ amines do not have intermolecular association. Intermolecular association is more in $1^°$ amines than in $2^°$ amines as there are two $H$-atoms available for $H$-bonding. Hydrocarbons are almost non-polar molecules and possess weak van der Waals forces and hence has lowest boiling point i.e., most volatile.