Question

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

Answer 1

In steam distillation, the compound with the lower boiling point distils first. The ortho-isomer of nitrophenol is steam volatile due to its lower boiling point compared to the para-isomer.

The difference in boiling points between the two isomers can be understood in terms of their structural differences. In the ortho-isomer, intramolecular hydrogen bonding occurs, but in the para-isomer, intermolecular hydrogen bonding occurs.