Question

The boiling point of a binary immsicible liquid mixture :

• A. is higher than that of either constituent.
• B. is lower than that of either constituent.
• C. is equal to atleast one of the constituents.
• D. cannot be predicted.

Answer 1

The correct option is B is lower than that of either constituent.

Immiscible Liquids
A mixture of two immiscible liquids will boil when the total vapour pressure is equal to the external pressure.
The boiling point of the mixture is thus, lower than that of either constituent.

Example:
$\text{B.P. of water (pure)}={100}^{\circ }C$
$\text{B.P. of benzene (pure)}={80.2}^{\circ }C$
$\text{B.P. of water and benzene mixture}={68.9}^{\circ }C$