# Vapour pressure of pure water at 298 K is 23.8 mm Hg. 50 g of urea (NH2CONH2) is dissolved in 850 g of water. The vapour pressure of water (in mm Hg) for this solution is :  1. 23. 40 2. 0.23  3. 12.87 4. 40 .14

Subtopic:  Raoult's Law |
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Boiling point of water at 750 mm Hg is 99.63°C. The amount of sucrose added to 500 g of water so that solution boils at 100°C is-
(Molal elevation constant for water is 0.52 K kg mol−1 )

1. 128.17 g
2. 121.67 g
3. 125.57 g
4. 116.27 g
Subtopic:  Elevation of Boiling Point |
62%
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The mass of ascorbic acid (Vitamin C, C6H8O6) to be dissolved in 75 g of acetic acid
to lower its melting point by 1.5°C, is
(Kf = 3.9 K kg mol−1)

1. 5.19 g
2. 5.08  g
3. 5.65 g
4. 5.48 g

Subtopic:  Depression of Freezing Point |
69%
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The osmotic pressure in pascals exerted by a solution prepared by dissolving 1.0 g of polymer of molar mass 185,000 in 450 mL of water at 37°C is-

1. 37 Pa
2. 35 Pa
3. 31 pa
4. 41 Pa
Subtopic:  Osmosis & Osmotic Pressure |
58%
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The molarity of solution obtained when 30 mL of 0.5 M H2SO4 solution diluted to 500 mL is:

1. 0.03 M
2. 0.0003 M
3. 3.0 M
4. 30 M
Subtopic:  Concentration Terms & Henry's Law |
81%
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The density of 20% (mass/mass) aqueous KI is 1.202 g mL-1. The molality of KI solution is:

1. 1.21 m
2. 1.91 m
3. 1.71 m
4. 1.51 m
Subtopic:  Concentration Terms & Henry's Law |
53%
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The density of 20% (mass/mass) aqueous KI is 1.202 g mL-1. The mole fraction of KI in the solution is:

1. 0.0223
2. 0.0343
3. 0.0163
4. 0.0263

Subtopic:  Concentration Terms & Henry's Law |
52%
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The vapour pressure of pure liquids A and B are 450 and 700 mm Hg respectively, at 350 K.  If total vapour pressure is 600 mm Hg then the composition of the vapour phase are-

1. XA=0.30; XB=0.70
2. XA=0.40; XB=0.60
3. XA=0.20; XB=0.90
4. XA=0.50; XB=0.50

Subtopic:  Raoult's Law |
From NCERT
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Henry’s law constant for CO2 in water is 1.67 × 108 Pa at 298 K. The quantity of CO2 in 500 mL of soda water when packed under 2.5 atm CO2 pressure at 298 K is-

1. 1.24 g
2. 1.45 g
3. 1.65 g
4. 1.85 g
Subtopic:  Concentration Terms & Henry's Law |
From NCERT