NEET 2026
- Exam
- NEET
- Year
- 2026
- Subject
- Chemistry
- Chapter
- Chapter
NEET 2026 · Chemistry · Chapter
Aniline (boiling point 184^ C ) is often purified from a crude...
Aniline (boiling point ) is often purified from a crude mixture using steam distillation. Which of the following statements correctly describe the principles of this purification process?
I. The aniline-water mixture will boil at a temperature strictly below .
II. At the boiling point of the mixture, the vapor pressure of aniline alone is equal to the atmospheric pressure.
III. Steam distillation is effective because aniline and water are completely miscible liquids.
IV. The mixture boils when the sum of the vapor pressures of water and aniline equals the atmospheric pressure.
I. The aniline-water mixture will boil at a temperature strictly below .
II. At the boiling point of the mixture, the vapor pressure of aniline alone is equal to the atmospheric pressure.
III. Steam distillation is effective because aniline and water are completely miscible liquids.
IV. The mixture boils when the sum of the vapor pressures of water and aniline equals the atmospheric pressure.
Options
- AI and IV only
- BI and II only
- CIII and IV only
- DI, II and III only
Correct answer
A. I and IV only
Step-by-step solution
Steam distillation is a separation process used to purify temperature-sensitive organic compounds that are immiscible with water.
In steam distillation, the mixture of immiscible liquids (aniline and water) boils when the sum of their individual vapor pressures equals the atmospheric pressure. This means . Therefore, Statement IV is correct, and Statement II is incorrect.
Because the total vapor pressure reaches atmospheric pressure at a lower temperature than the boiling point of either pure component, the mixture will boil at a temperature below the boiling point of pure water (). Therefore, Statement I is correct.
Steam distillation is specifically applicable to liquids that are immiscible with water. Aniline and water are immiscible, not completely miscible. Therefore, Statement III is incorrect.
Thus, only statements I and IV are correct.
Answer: I and IV only
In steam distillation, the mixture of immiscible liquids (aniline and water) boils when the sum of their individual vapor pressures equals the atmospheric pressure. This means . Therefore, Statement IV is correct, and Statement II is incorrect.
Because the total vapor pressure reaches atmospheric pressure at a lower temperature than the boiling point of either pure component, the mixture will boil at a temperature below the boiling point of pure water (). Therefore, Statement I is correct.
Steam distillation is specifically applicable to liquids that are immiscible with water. Aniline and water are immiscible, not completely miscible. Therefore, Statement III is incorrect.
Thus, only statements I and IV are correct.
Answer: I and IV only