Question

During steam distillation of a mixture of o-nitrophenol and p-nitrophenol

(a)  vapours of o-nitrophenol are carried by steam because of its lower boiling point due to chelation.

(b)  vapours of o-nitrophenols are carried by steam because of its lower boiling point and solubility in steam.

(c)  vapours of o-nitrophenol are carried by steam because its boiling point is reduced by steam.

(d)  vapours of p-nitrophenol are carried by steam because of its lower boiling point

Answer 1

Correct option (a) vapours of o-nitrophenol are carried by steam because of its lower boiling point due to chelation.

Explanation:

Only o-nitrophenol is capable of forming intramolecular H-bonding (chelation) which leads to its lower b.p. (less than 100°C) and also lower solubility in water (steam).