Vapour pressure of a solution of non-volatile solute is — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

When the non-volatile solute is added to the solvent the vapour pressure of the solution decreases. Now according to Raoult’s law, the pressure of the solvent (let P1) in the solution is given by, 0 1 1 1 P x P SOLUTIONS 35 Where, 0 1P is the vapour pressure of pure solvent, 1 x is the mole fraction of a solute, and P1 is the pressure of the solution. We can say that the vapour pressure of a non- volatile solute is directly proportional to the mole fraction of the solvent. It is, P x Thus, (a) is the correct option.