Colligative Properties — Prelims Questions

Which of the following 0.1 M aqueous solutions will have the lowest freezing point?

The osmotic pressure of a solution containing 34.2 g of sucrose (Molar Mass = 342 g/mol) in 1 L of solution at $27^\circ\text{C}$ is (Given: $R = 0.0821\text{ L atm mol}^{-1}\text{ K}^{-1}$):

An aqueous solution freezes at $-0.186^\circ\text{C}$. What is the boiling point of the solution? ($K_f = 1.86\text{ K kg mol}^{-1}$, $K_b = 0.512\text{ K kg mol}^{-1}$ for water)

Which of the following statements about osmotic pressure is INCORRECT?

The vapor pressure of pure benzene at a certain temperature is $0.850\text{ bar}$. A non-volatile, non-electrolyte solid weighing $0.5\text{ g}$ when added to $39.0\text{ g}$ of benzene (Molar Mass = $78\text{ g/mol}$) gives a solution with a vapor pressure of $0.845\text{ bar}$. What is the molar mass of the solid substance?

A 5% (w/v) solution of a non-volatile solute has an osmotic pressure of $4.98\text{ atm}$ at $27^\circ\text{C}$. What is the molar mass of the solute? (Given: $R = 0.0821\text{ L atm mol}^{-1}\text{ K}^{-1}$)