The partial pressure of ethane over a saturated solution containing 6.56 X 10^-2 g of ethane is 1 bar. If the solution contains 5.00 X 10^-2 g of ethane, then what shall be the partial pressure of the gas?

1. 0.76 bar

2. 0.16 bar

3. 1.16 bar

4. 3.12 bar

The freezing point depression constant for water is 1.86 ^oC m^-1. If 5.00 g Na₂SO₄ is dissolved in 45.0 g H₂O, the freezing point is changed by -3.82 ^oC. The van’t Hoff factor for Na₂SO₄ is:

The mixture that shows positive deviation from Raoult's law is-

1. Benzene + Toluene

2. Acetone + Chloroform

3. Chloroethane + Bromoethane

4. Ethanol + Acetone

Considering the formation, breaking and strength of hydrogen bond, predict which of the following mixtures will show a positive deviation from Raoult’s law?

1.  Methanol and acetone

2.  Chloroform and acetone

3.  Nitric acid and water

4.  Phenol and aniline

The value of Henry's constant K_H -

1. Increases with increase in temperature.

2. Decreases with increase in temperature.

3. Remains constant.

4. First increases then decreases.

Van't Hoff factor (i) is given by the expression:

a. $i=\frac{\text{ Normal molar mass }}{\text{abnormal molar mass.}}$

b. $i=\frac{\text{ Abnormal molar mass }}{\text{normal molar mass. }}$

c. $i=\frac{\text{ Observed colligative property }}{\text{calculated colligative property. }}$

d. $i=\frac{\text{ Calculated colligative property }}{\text{observed colligative property.}}$

The correct choice among the given options are:

1. (a, b)

2. (b, c)

3. (c, d)

4. (a, c)

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]

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):

A solution of urea (molar mass 56 g mol^–1) boils at 100.18 ºC at atmospheric pressure. If K_f and K_b for water are 1.86 and 0.512 K kg mol^–1 respectively, the above solution will freeze at:

1. –6.54 ºC

2. –0.654 ºC

3. 6.54 ºC

4. 0.654 ºC