Which of the following should be most volatile?

1. II

2. IV

3. I

4. III

HINT: H-bonding is the strong intermolecular force
EXPLAINATION(2) -1o and 2o amines have higher boiling points due to intermolecular H-bonding but less volatile than amines and hydrocarbons of comparable molecular mass. Further, because of polar C-N bonds, 3o amines are more polar than hydrocarbons which are almost non-polar. Hence. due to weak dipole-dipole interactions, 3o amines have a higher boiling point (i.e., less volatile) than hydrocarbons.
In other words, hydrocarbons are more volatile among given compounds as amine are Less volatile than hydrocarbon.