Which of the following is steam volatile?

The correct option is B

o-Nitrophenol

The explanation for the correct option

(B) o-Nitrophenol

• A compound if it distills under steam distillation then it is said to be steam volatile.
• To purify volatile organic substances by steam distillation, the compound must have its melting point lesser than the boiling point of water.
• Here, o-Nitrophenol involves intramolecular hydrogen bonding, so it cannot form a hydrogen bond with other molecules
• Hence it has a lower melting point and it can be distilled by steam distillation

Hence, Option (B) o-Nitrophenol is correct

The explanation for the incorrect options

(A) Phenol

• Phenol does not have intramolecular hydrogen bonding, it can effectively have hydrogen bonds with other molecules.
• It cannot be distilled by steam distillation

(C) m-Nitrophenol

• m-Nitrophenol does not have intramolecular hydrogen bonding, it can effectively have hydrogen bonds with other molecules.
• It cannot be distilled by steam distillation

(D) p-Nitrophenol

• p-Nitrophenol does not have intramolecular hydrogen bonding, it can effectively have hydrogen bonds with other molecules.
• It cannot be distilled by steam distillation

Therefore, Option (B) o-Nitrophenol is correct