The vapour pressure of toluene is 59.1 torr at 313.75 K and 298.7 torr at 353.15 K. Calculate, the molar heat of vaporisation.

1. 37888 J mol^-1

2. 27188 J mol^-1

3.  12834 J mol^-1

4. 571328 J mol^-1

The vapour pressure of a pure liquid solvent A is 0.80 atm. When a non-volatile substance B is added to the solvent, its vapour pressure drops to 0.60 atm.
Mole fraction of the component B in the solution is:

The lowest boiling point, if concentration is fixed at 0.1 M in aqueous solution, is given by which of the following solutions?

a. K₂SO₄

b. NaCl

c. Urea

d. Glucose

1. a, b

2. b, c

3. c, d

4. d, a

The boiling point of acetic acid is 118.1$°\mathrm{C}$ and its latent heat of vaporisation is 121 cal/gm. A solution containing 0.4344 gm anthracene in 44.16 gm acetic acid boils at 118.24$°\mathrm{C}$. What is the molecular wt. of anthracene ?

1. 122

2. 178

3. 105

4. 154

Which solution will have the highest boiling point ?

1. 1 (M) C₆H₁₂O₆ solution

2. 1 (M) NaCl solution

3. 1 (M) BaCl₂ solution

4. 1 (M) CO(NH₂)₂ solution

A 2.0% solution by weight of urea in water shows a boiling point elevation of 0.18 deg [Molecular weight of urea=60]. Calculate the latent heat of vaporization per gram of water.

1. 495.3 cal/g

2. 560.3 cal/g

3. 525.8 cal/g

4. 501.3 cal/g

A solution of 18 g of glucose in 1000 g of water is cooled to -0.2 ^oC. The amount of ice separating out from this solution is -

[K_f(H₂O) = 1.86 K molal^-1]

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

In a dilute solution, any colligative property depends on 

1. The total number of neutral species in the solution

2. The total number of ionic species in the solution

3. The total number of species irrespective of whether they are ionic or non-ionic.

4. The types of forces operating between the non-ionic species, ionic species and the solvent molecules

An aqueous solution of 2 percent non volatile solute exerts a pressure of 1.004 bar at the boiling point of the solvent. What is the molecular mass of the solute ?

1. 9.19 g mol^-1

2. 41.3 g mol^-1

3. 71.2 g mol^-1

4. 50.4 g mol^-1