The vapour pressure of pure benzene and toluene are 160 and 60 torr respectively. The mole fraction of toluene in vapour phase in contact with an equimolar solution of benzene and toluene is -

1.	0.50	2.	0.6
3.	0.27	4.	0.73

Osmotic pressure is 0.0821 atm at a temperature of 300 K. Find concentration in mole/litre [Roorkee 1990]

(1) 0.033

(2) 0.066

(3) 0.33 × 10^–2

(4) 3

The osmotic pressure of 5 % (mass-volume) solution of cane sugar at 150 °C (mol. mass of sugar = 342 g/mole) is:

A solution containing 3.3 g of a substance in 125 g of benzene (b.p. 80°C) boils at 80.66°C. If K_b for one litre of benzene is 3.28°C, the molecular weight of the substance shall be 

1. 127.20

2. 131.20

3. 137.12

4. 142.72

An aqueous solution containing 1 g of urea boils at 100.25 °C. The aqueous solution containing 3 g of glucose in the same volume will boil at:
1. 100.75 °C
2. 100.5 °C
3. 100 °C
4. 100.25 °C

Solution of sucrose (Mol. Mass = 342) is prepared by dissolving 34.2 gm of it in 1000 gm of water. Freezing point of the solution is (K_f for water is 1.86 K kg mol^–1) [AIEEE 2003]

(1) 272.814 K

(2) 278.1 K

(3) 273.15 K

(4) 270 K

A solution containing 6.8 g of a non-ionic solute in 100 g of water was found to freeze at −0.93 ^oC. The freezing point depression constant of water is 1.86. The molecular weight of the solute is-

The molar freezing point constant for water is 1.86°C/mole. If 342 g of cane sugar $\left({\mathrm{C}}_{12}{\mathrm{H}}_{22}{\mathrm{O}}_{11}\right)$ is dissolved in 1000 g of water, the solution will freeze at 

1. –1.86°C

2. 1.86°C

3. –3.92°C

4. 2.42°C

The depression in freezing point of 0.01 M aqueous solutions of urea, sodium chloride and sodium sulphate is in the ratio of [Roorkee 1990; DCE 1994]

(1) 1 : 1 : 1

(2) 1 : 2 : 3

(3) 1 : 2 : 4

(4) 2 : 2 : 3

The Van't Hoff factor for 0.1 M $\mathrm{Ba}{\left({\mathrm{NO}}_3\right)}_2$ solution is 2.74. The degree of dissociation is [IIT 1999]

(1) 91.3%

(2) 87%

(3) 100%

(4) 74%