The ratio between lowering of vapour pressure of solution and mole fraction of solute is equal to — Solutions and Colligative Properties Chemistry Question

💡 Solution & Explanation

Lowering of vapour pressure $\Delta P = P^\circ \cdot X_{\text{solute}}$. Thus, $\Delta P / X_{\text{solute}} = P^\circ$, which is the vapour pressure of the pure solvent. Therefore, correct answer is B.