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%

Which of the following is not a colligative property?

• Elevation in boiling point

• Depression in freezing point

• Osmotic pressure

• Lowering of vapour pressure

3 g of urea is dissolved in 45 g of H₂O. The relative lowering in vapour pressure is

• 0.05

• 0.04

• 0.02

• 0.01

Which of the following aqueous solution will exhibit highest boiling point?

• 0.01M urea

• 0.01 M KNO₃

• 0.01M Na₂SO₄

• 0.015M C₆H₁₂O₆

Which of the following is not a colligative property?

• Osmotic pressure

• Optical activity

• Depression in freezing point

• Elevation in boiling point

Which of the following aqueous solution has the highest freezing point?

• 0.1M surcose

• 0.01 M NaCl

• 0.1 M NaCl

• 0.01 M Na₂SO₄

When an electrolyte is dissociated in solution, the van't Hoff factor (i) is

• > 1

• < 1

• = 0

• = 1