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

145.

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

When KBr is dissolved in water, K⁺ ions are

• hydrated

• hydrolysed

• reduced 

• oxidised

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