Which of the following solutions will exhibit highest boiling point?
0.01M Na2SO4 (aq)
0.1M KNO3 (aq)
0.015 M urea(aq)
0.015 M glucose(aq)
Osmotic pressure observed when benzoic add is dissolved in benzene is less than that expected from theoretical considerations. This is because:
benzoic acid is an organic solute
benzoic acid has higher molar mass than benzene
benzoic acid gets assoicated in benzene
benzoic acid gets dissociated in benzene
The mass of glucose that should be dissolved in 50 g of water in order to produce the same lowering of vapour pressure as is produced by dissolving 1 g of urea in the same quantity of water is:
1g
3g
6g
18g
Which of the following can be measured by the Ostwald-Walker dynamic method?
Relative lowering of vapour pressure
Lowering of vapour pressure
Vapour pressure of the solvent
All of the above
D.
All of the above
By Ostwald-Walker dynamic method, the relative lowering of vapour pressure, lowering of vapour pressure and vapour pressure of the solvent, all can be measured. In this method, the apparatus used, contains two bulbs : bulb A contains solution and bulb B contains solvent. The loss of weight in bulb B gives the lowering of vapour pressure and total loss of weight in both the tubes gives the vapour pressure of the solvent and Relative lowering of vapour pressure
=
When a sulphur sol is evaporated sulphur is obtained. On mixing with water sulphur sol is not formed. The sol is
lyophilic
reversible
hydrophobic
hydrophilic
An aqueous solution containin g 6.5 g of NaCl of 90% purity was subjected to electrolysis. After the complete electrolysis, the solution was evaporated to get solid NaOH. The volume of 1 M acetic acid required to neutralise NaOH obtained above is
1000 cm3
2000 cm3
100 cm3
200 cm3
Vapour pressure of pure 'A' is 70 mm of Hg at 25°C. It forms an ideal solution with 'B' in which mole fraction of A is 0.8. If the vapour pressure of the solution is 84 mm of Hg at 25°C, the vapour pressure of pure 'B' at 25°C is
28 mm
56 mm
70 mm
140 mm
A 6% solution of urea is isotonic with
1 M solution of glucose
0.05 M solution of glucose
6% solution of glucose
25% solution of glucose
In countries nearer to polar region, the roads are sprinkled with CaCl2. This is
to minimise the water and tear of the roads.
to minimise the snow fall
to minimise pollution
to minimise the accumulation of dust on the road