Shown below is the phase diagram for a typical liquid mixture of two components, A and B 150
130--___- 110 70 50 100%-80%-60%--40%-20%--0% 0%-20%-40%-60%-80%-100% A B
What is the significance of the horizontal line between points X and Y? A boiling liquid with
composition X will produce vapor with composition Y. O A boiling liquid with composition Y
will produce a vapor with composition X. O The length of the line XY corresponds to the
difference in boiling point of components A and B. The point X gives the vapor composition of
the less volatile component and Y gives the vapor composition of the more volatile component.
The linc gives the difference. Using the phase diagram determine the molar composition of the
vapor in equilibrium with a boiling liquid that has a composition of 50% A and 50 % B
Percentage vapor composition A- Percentage vapor composition B What is the boiling point of
this liquid? Boiling point- °C
Solution
The point X gives the vapour composition of the less volatile components and y gives the vapour
composition of more volatile components and boiling point of water is 100°c