The osmotic pressure of 5% (mass-volume) solution of cane sugar at 150°C (mol. mass of sugar = 342) is:
1. 4 atm
2. 5.07 atm
3. 3.55 atm
4. 2.45 atm
A solution containing 3.3 g of a substance in 125 g of benzene (b.p. 80 °C) boils at 80.66 °C. If Kb for one litre of benzene is 3.28 °C m-1, the molecular weight of the substance shall be -
1. 127.20 g mol-1
2. 131.20 g mol-1
3. 137.12 g mol-1
4. 142.72 g mol-1
The molal b.p. constant for water is . When 0.1 mole of sugar is dissolved in 200 g of water, the solution boils under a pressure of 1 atm at
(1) 100.513°C
(2) 100.0513°C
(3) 100.256°C
(4) 101.025°C
The molality of a solution containing a certain solute, if there is a freezing point depression of 0.184 °C, is-
(Kf = 18.4)
1. 0.01 m
2. 10 m
3. 0.05 m
4. 100 m
The molal freezing point constant for water is 1.86°C/mole. If 342 g of cane sugar 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 Ba(NO3)2 solution is 2.74. The degree of dissociation is -
1. 91.3 %
2. 87 %
3. 100 %
4. 74 %
The latent heat of vaporization of water is 540 cal g-1 at 100 oC. Kb for water is:
1.
2.
3.
4.
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 vapour pressure of a solvent A is 0.80 atm. When a non-volatile substance B is added to this solvent its vapour pressure drops to 0.6 atm. the mole fraction of B in the solution is [MP PMT 2000]
(1) 0.25
(2) 0.50
(3) 0.75
(4) 0.90