Question

Which of the following are correct for purification by steam distillation?

• A. Impurities must be non - volatile.
• B. The liquid must be completely immiscible with water.
• C. The vapor pressure of the liquid must be sufficiently high.
• D. All are correct

Answer 1

The correct option is D All are correct

For steam distillation technique, two immiscible liquids must be present. Both of the liquids will be in equilibrium with their vapours.
Agitated mixtures of immiscible liquids will boil at a temperature lower than the boiling point of either of the pure liquids.
The total vapour pressure is then the sum of the individual vapour pressures.