Question

A graph showing vapour pressure against mole fraction of an ideal solution with volatile components A and B are shown below :

1. Which law is supported by the graph?

2. State the law.

3. Resketch the graph if the attraction between A and B is greater than that between A-A and B-B.

Answer 1

1. Raoult’s law.

2. Raoult’s law states that vapour pressure of a volatile component in a solution is the product of vapour pressure of that component in the pure form and mole fraction of that component in the solution.

3. If the A-B attraction is greater than A-A and B-B attractions the liquid mixture behaves as a non-ideal solution with negative deviation.