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

11.61 

In ortho nitrophenol there is intra-molecular H bonding, whereas in para-nitrophenol there is inter-molecular H bonding, as shown below:

And because of that para-nitrophenol get tightly bounded with water and ortho nitrophenol is steam volatile and it will leave the solution.