Question

State Raoult’s law. 

Answer 1

Raoult’s law states that the partial vapour pressure of any volatile component of a solution is equal to the vapour pressure of the pure component multiplied by its mole fraction in the solution. 

Answer 2

For a solution of volatile liquids, the partial vapour pressure of each component in the solution at a particular temperature is equal to the product of the vapour pressure of the component in the pure state and its mole fraction in the solution.

Mathematically, for a binary solution:

\[\ce{P_A = P{^{\circ}_{A}}\chi_A}\] and 

\[\ce{P_B = P{^{\circ}_{B}}\chi_B}\]

The total vapour pressure is:

\[\ce{P_{total} = P_A + P_B = P{^{\circ}_{A}}\chi_A + P{^{\circ}_{B}}\chi_B}\]