While separating a mixture of ortho- and para-nitrophenols steam distillation, name the isomer which will be steam volatile. Give reason.

Explanation

o-nitrophenol is steam volatile while p-nitrophenol is not. This is no account of intramolecular hydrogen bonding in the molecules of o-nitrophenol. As a result, its boiling point is less than that of p-nitrophenol in which the molecules are linked by intermolecular hydrogen bonding. for more details, consult section 15 (Physical properties of phenols).