Solutions — Prelims Questions

A solution is prepared by dissolving 18 g of glucose (Molar mass = 180 g/mol) in 500 g of water. The molality of the solution is:

Which of the following statements is INCORRECT regarding ideal solutions?

The Henry's Law constant for oxygen dissolved in water is $4.34 \times 10^4\,\text{atm}$ at $25^\circ\text{C}$. If the partial pressure of oxygen in the air is $0.2\,\text{atm}$, what is the mole fraction of oxygen dissolved in water?

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 whose vapor pressure is $0.845\,\text{bar}$. What is the molar mass of the solid substance?

An aqueous solution freezes at $-0.186^\circ\text{C}$. Given $K_f$ for water is $1.86\,\text{K kg mol}^{-1}$. The boiling point of this solution will be (Given $K_b$ for water is $0.512\,\text{K kg mol}^{-1}$):

Which of the following $0.1\,\text{M}$ aqueous solutions will have the highest osmotic pressure?