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

425.

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

Cooking is fast in a pressure cooker, because

• food particles are effectively smashed

• water boils at higher temperature inside the pressure cooker

• food is cooked at constant volume

• loss of heat due to radiation is minimum

1 g of silver gets distributed between 10 cm³ of molten zinc and 100 cm³ of molten lead at 800°C. The percentage of silver still left in the lead layer is approximately

• 2

• 5

• 3

• 1

Asolution of two liquids boils at a temperature more than the boiling point of either of them. Hence, the binary solution shows

• negative deviation from Raoult's law

• positive deviation from Raoult's law

• no deviation from Raoult's law

• positive or negative deviation from Raoult's law depending upon the composition

A solution of 1.25 of 'P' in 50 g of water lowers freezing point by 0.3°0. Molar mass of 'P' is 94. K_f(water) = 1.86 K kg mol^-1. The degree of association of 'P' in water is

• 80%

• 60%

• 65%

• 75%