A mixture of o-nitrophenol and p-nitrophenol can be separated by

Options

A. distillation
B. steam distillation
C. crystallization
D. fractional crystallization

Answer

A

Explanation

p-nitrophenol has more boiling pont due to intermolcular hydrogen bonding.
separation by distillation.

In the o-compound, the hydroge bonding is intramolecular, andso the molecul behaves as a single unit. Hydrogen bonding in the p-compound is intermolecular. Thus, we are dealing with associated molecules, which behave as a large molecule with high molecular weight, there by giving rise to a high boiling point (much higher tha that of the monomer).
Since we have assumed that the o-compound has the thpe of hydrogen bonding shown, this presumably is also possible for the p-compound. On the other hand, hydrogen bonding betwen hydroxyl groups in the -compound is possible.