A 0.1 molal aqueous solution of a weak acid (HA) is 30 % ionized. If K_f for water is 1.86 °C/m, the freezing point of the solution will be:

1.	–0.24 °C	2.	–0.18 °C
3.	–0.54 °C	4.	–0.36 °C

200 mL of an aqueous solution contains 1.26 g of protein. The osmotic pressure of this solution at 300 K is found to be 2.57 × 10^–3 bar. The molar mass of protein will be:

(R = 0.083 L bar mol^–1 K^–1):

Isotonic solutions have the same:

1. Vapour pressure

2. Freezing temperature

3. Osmotic pressure

4. Boiling temperature

If 8 g of a non-electrolyte solute is dissolved in 114 g of n-octane to reduce its vapor pressure to 80 %, the molar mass (in g mol^–1) of the solute is:

[Molar mass of n-octane is 114 g mol^–1]

The positive deviations from Raoult’s law mean the vapour pressure is:

1. Higher than expected.
2. Lower than expected.
3. As expected.
4. None of the above

The type of inter-molecular interactions present in:

Henry’s law constant for the solution of methane in benzene at 298 K is 4.27 × 10⁵ mm Hg. The mole fraction of methane in benzene at 298 K under 760 mm Hg will be:

1. 1.85 × 10^–5

2. 192 × 10^–4

3. 178 × 10^–5

4. 18.7 × 10^–5

The solubility of a gas in a liquid decreases with an increase in temperature because:

To minimize the painful effects accompanying deep sea diving, oxygen diluted with less soluble helium gas is used as breathing gas by the divers. This is an example of the application of: