Heptane and octane form an ideal solution. At 373 K, the vapour pressures of the two liquid components are 105.2 kPa and 46.8 kPa respectively. The vapour pressure of a mixture of 26.0 g of heptane and 35 g of octane would be -

1. 43.45 kPa

2. 78.96 Pa

3. 73.43 kPa 

4. 65.72 Pa

A 5 % solution (by mass) of cane sugar in water has freezing point of 271 K. Freezing point of 5 % glucose in water would be -

(freezing point of pure water is 273.15 K)

1. 279.24 K

2. - 269.06 K

3. 275. 42 ^oC

4. 269.06 K

At 300 K, 36 g of glucose present in a litre of its solution has an osmotic pressure of 4.98 bar. Concentration at which osmotic pressure of the solution becomes 1.52 bar at the same temperature, would be -

1. 0.06 M

2. 0.12 M

3. 0.08 M

4. 0.36 M

 The correct sequence of order of increasing solubility in the n-octane is-

1. Cyclohexane < CH₃CN < CH₃OH < KCl

2. KCl < CH₃OH < CH₃CN < Cyclohexane

3. KCl < CH₃OH > CH₃CN < Cyclohexane

4. None of the above

If the density of lake water is 1.25 g mL^–1 and contains 92 g of Na⁺ ions per kg of water, then the molality of Na⁺ ions will be-

The Vapour pressure of water at 293 K is 17.535 mm Hg. The vapour pressure of water at 293 K when 25 g of glucose is dissolved in 450 g of water is-

1. 18.54 mm of Hg

2. 17.44 mm of Hg

3. 12.35 mm of Hg

4. 18.67 mm of Hg

Benzene and toluene form an ideal solution over the entire range of composition. The vapour pressure of pure benzene and toluene at 300 K are 50.71 mm Hg and 32.06 mm Hg respectively.

The mole fraction of benzene in vapour phase, if 80 g of benzene is mixed with 100 g of toluene, would be -

1. 0.41

2. 0.68

3. 0.72

4. 0.59

The osmotic pressure of a solution prepared by dissolving 25 mg of K₂SO₄ in 2 litres of water at 25° C, assuming that it is completely dissociated is-

 $1. 2.76 \times {10}^{-3} \mathrm{atm}$
$2. 5.39 \times {10}^{-4} \mathrm{atm}$
$3. 5.27 \times {10}^{-3} \mathrm{atm}$
$4. 3.19 \times {10}^{-3} \mathrm{atm}$

Mole fraction of benzene in solution containing 30% by mass in carbon tetrachloride is

1. 0.46

2. 0.54

3. 0.27

4. 0.35

What is the mass of urea (NH₂CONH₂) required in making 2.5 kg of 0.25 molal aqueous solution?

1. 74 g

2. 69 g

3. 33 g

4. 37 g