Most suitable method of separation of a 1:1mixture of ortho and para- nitrophenols is
 

It is most appropriate to separate a 1:1 mixture of ortho and para nitrophenols using steam distillation because ortho nitrophenol contains intramolecular H-bonds. Steam distillation is a process used to recover volatile compounds with a high boiling point from inert and complex matrices, solid or liquid.