The lubricating action of an oil is more if it possess:-

(1) High vapour pressure

(2) low vapour pressure

(3) High surface tension

(4) High density

When 0.1 m CH₃COOH is present in a solvent it shows elevation in boiling point of 0.75$°\mathrm{C}$. Acid dissociation constant will be -(K_b=5 K Kg mol^-1) (1M =1m)

(1) 5 X 10^-2

(2) 5 X 10^-3

(3) 10^-2

(4) 10^-3 

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 non-volatile solute is dissolved in water. If its degree of association is 50%. What will be its freezing point when the boiling point is 100.52$°\mathrm{C}$. [K_b=0.52 K kg mol^-1, K_f=1.86K kg mol^-1]

1. -0.52 K

2. -0.52$°\mathrm{C}$

3. -1.86$°\mathrm{C}$

4. 275.01 K

When 36 g of a solute having the emperical formula CH₂O is dissolved in 1.2 kg of water, the solution freezes at -0.93$°\mathrm{C}$. What is the molecular formula of solute (K_f=1.86 kg K mol^-1)

(1) C₂H₄O

(2) C₂H₂O₂

(3) C₂H₄O₃

(4) C₂H₄O₂

If partial pressure of oxygen is 0.5 atm and K_H = 1.4 × 10^-3 M/atm, then the amount of oxygen dissolved in 100 ml water at 298K is-

A solute x when dissolved in solvent associates to form a pentamer. The value of van't hoff factor (i) for the solute will be:-

1. 0.5

2. 5

3. 0.2

4. 0.1

What amount of CaCl₂(i=2.47) is dissolved in 2L water so that its osmotic pressure is 0.5 atm at 27$°\mathrm{C}$?

1. 13.42 g

2. 19.24 g

3. 8.834 g

4. 1.820 g

One litre aqueous solution of sucrose (molar mass = 342 g/mol) weighing 1015 g is found to record an osmotic pressure of 4.8 atm at 293K. What is the molality of the sucrose solution ? (R= 0.0821 L atm K^-1 mol^-1) :

(1) 0.84

(2) 0.21

(3) 0.42

(4) 0.63

The total vapor of a solution of liquid A and liquid B is 600 torr. The mole fraction of component A in the liquid phase is 0.7 and in the vapor phase is 0.35. The vapor pressure of pure A and B are respectively

(1) 300 torr, 130 torr

(2) 1300 torr, 130 torr

(3) 300 torr, 1300 torr

(4) 300 torr, 300 torr