Which of the following units is useful in relating the concentration of a solution with its vapour pressure?
(i) mole fraction
(ii) parts per million
(iii) mass percentage
(iv) molality
The answer is the option (i) Vapour pressure and the concentration (mole fraction) of solution are related. Raoult’s law states that the vapour pressure of a component is directly proportional to the mole fraction of the component.
where,