The mass of urea (NH2CONH2) required to  make 2.5 kg of 0.25 molal aqueous solution is: 1. 39 g 2. 37 g 3. 41 g 4. 35 g

Subtopic:  Concentration Terms & Henry's Law |
77%
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Calculate the molarity of the KI solution, provided its density is 1.202 g mL-1 and it consists of a 20% (mass/mass) concentration.

1. 1.25 M
2. 1.95 M
3. 1.45 M
4. 2.15 M
Subtopic:  Concentration Terms & Henry's Law |
62%
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The solubility of H2S in water at STP is 0.195 m, The value of Henry’s law constant will be:
 1 274 atm 2 285 atm 3 295 atm 4 278 atm
Subtopic:  Concentration Terms & Henry's Law |
52%
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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 |
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The vapour pressure of pure liquids A and B are 450 and 700 mm Hg respectively, at 350 K.  If the 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 |
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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 |
64%
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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 |
59%
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