JEE Main · 2004 · 24 Apr 2004 · Offline · Solutions

Test each statement in turn. Raoult's law rightly says a component's vapour pressure over a solution is proportional to its mole fraction. The osmotic-pressure ordering $\mathrm{BaCl}{}_2>\mathrm{KCl}>\mathrm{CH}{}_3\mathrm{COOH}>\text{sucrose}$ is correct, matching van't Hoff factors of about 3, 2, a little over 1, and 1. The relation $\pi =MRT$ is the van't Hoff equation and holds. The false claim is that two sucrose solutions of equal molality in different solvents give the same freezing-point depression; since $\Delta T_f=K_{f}m$ and $K_f$ changes from solvent to solvent, that cannot be true.