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

Which of the following pairs exhibit positive deviation from Raoult's law?
 

(i) Chloroform and Acetone

(ii) Carbon disulphide and Acetone

(iii) Ethanol and Acetone

(iv) Phenol and Aniline

1. i and ii

2. ii and iii

3. i and iv

4. ii and iv

A solution of acetone in ethanol:

1. Shows a negative deviation from Raoult's law.

2. Shows a positive deviation from Raoult's law.

3. Behaves like a near ideal solution.

4. Obeys Raoult's law.

The correct statement regarding a solution of two components A and B exhibiting positive deviation from ideal behaviour is :

The vapour pressures of pure benzene and toluene are 160 torr and 60 torr, respectively. The mole fraction of toluene in the vapour phase in contact with an equimolar solution of benzene and toluene will be:

1. 0.50

2. 0.6

3. 0.27

4. 0.73

1. Benzene + Toluene

2. Acetone + Chloroform

3. Chloroethane + Bromoethane

4. Ethanol + Acetone

When the attraction between A — B is more than that of A-A and B— B, the solution will show deviation from Raoult’s law:

(1) Positive

(2) Negative

(3) No

(4) Cannot be Predicted 

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

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

For a binary ideal liquid solution, the curve that represents the variation in total vapor pressure versus composition of the solution is:

a.		b.
c.		d.

The correct option is:
1. a and b
2. b and c
3. c and d
4. a and d