Question

A mixture of two immiscible liquids at a constant pressure of 1 atm boils at a temperature-

• A. Equal to the normal boiling point of more volatile liquid.
• B. Equal to the mean of the normal boiling points of the two liquids.
• C. Greater than the normal boiling point of either of the liquid.
• D. Smaller than the normal boiling point of either of the liquid.

Answer 1

Answer: (D)

Smaller than the normal boiling point of either of the liquid.

The vapour pressure of a mixture of two immiscible liquids is the sum of their vapour pressures in the pure states. It is independent of their relative amounts. Hence, the boiling point of the mixture is less than that of either of the liquids, and remains constant throughout.