Question Detail

CHM 102 Isolation and Purification of Organic Compounds Objective Question

Question

In steam distillation, why do the liquids boil at a lower temperature than their normal boiling points?
Options
A Increased pressure
B Decreased atmospheric pressure
C Aqueous tension (vapor pressure of water) contributes to total pressure
Correct Answer
D Chemical reaction with steam
Correct Answer

Option C is the correct answer.

Detailed Explanation

The total pressure equals the sum of the vapor pressures of water and the organic components (aqueous tension). When this sum equals atmospheric pressure, boiling occurs at a lower temperature than the normal boiling point of the organic compound.

Hint

Total pressure = aqueous tension + vapor pressure of liquid components.

Question Info