List of top Chemistry Questions on Colligative Properties and Determination of Molar Mass

Which of the following salts would have the same value of the van't Hoff factor as that of \(\text{Al}(\text{NO}_3)_3\) in aqueous solution?
Assume complete dissociation of electrolytes.
(A) \(\text{K}_2\text{SO}_4\)
(B) \(\text{KCl}\)
(C) \(\text{Al}_2(\text{SO}_4)_3\)
(D) \(\text{K}_3[\text{Fe}(\text{CN})_6]\)
Choose the correct answer from the options given below:

Which of the following statements are true for the elevation of boiling point?
(A) The boiling point of a solution is always higher than the boiling point of the pure solvent in which the solution is prepared.
(B) The boiling point of a solution is always lower than the boiling point of the pure solvent in which the solution is prepared.
(C) The elevation of boiling point is directly proportional to the molal concentration of the solute in solution.
(D) Unit of \(K_b = \text{K kg mol}^{-1}\)
Choose the correct answer from the options given below:

Calculate the vapour pressure of a solution containing \( 61 \, g \) of benzoic acid (molar mass \( = 122 \, g \, mol^{-1} \)) dissolved in \( 500 \, g \) of benzene when the vapour pressure of pure benzene at this temperature of experiment is \( 66 \, torr \). Assume complete dimerization of benzoic acid in benzene.

A solution containing \( 8.0 \text{ g} \) of a non-volatile solute in \( 100 \text{ g} \) of diethyl ether boils at \( 36.86 ^\circ\text{C} \) whereas pure diethyl ether boils at \( 35.60 ^\circ\text{C} \). Determine the molar mass of the solute. (\( K_b \) for diethyl ether = \( 2.02 \text{ K kg mol}^{-1} \))