MEDIUM
Earn 100

Mass of Urea NH2CONH2 required to be dissolved in 1000 g of water in order to reduce the vapour pressure of water by 25% is _______ g. (Nearest integer)

Given : Molar mass of N, C, O and H are 14, 12, 16 and 1 g mol-1 respectively.

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Important Questions on Solutions

MEDIUM
The vapour pressure of a solution of glucose is 720 mmHg at 100oC. What is the mole fraction of water in this solution?
MEDIUM
The vapour pressure of acetone at 20oC is 185 torr. When 1.2 g of a non-volatile substance was dissolved in 100 g of acetone at 20oC , its vapour pressure was 183 torr. The molar mass (g mol-1) of the substance is:
MEDIUM
If 8 g of a non-electrolyte solute is dissolved in 114 g of n-octane to reduce its vapour pressure to 80%, the molar mass (in g mol-1) of the solute is [Given that molar mass of n-octane is 114 g mol-1]
EASY
vapour pressure of water at 293 K is 17535 mm Hg. The vapour pressure of water at 293 K containing 25 g of glucose dissolved in 450 g of water is
MEDIUM
At room temperature, a dilute solution of urea is prepared by dissolving 0.60 g of urea in 360 g of water. If the vapour pressure of pure water at this temperature is 35 mm Hg , lowering of vapour pressure will be:
(molar mass of urea =60 g mol-1 )
EASY
Benzene and toluene form nearly ideal solution. At 20°C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20°C for a solution containing 78 g of benzene and 46 g of toluene (in torr) is
EASY
A set of solutions is prepared using 180 g of water as a solvent and 10 g of different non-volatile solutes A, B and C. The relative lowering of vapour pressure in the presence of these solutes are in the order [Given, molar mass of A=100 g mol-1 ; B=200 g mol-1 ; C=10,000 g mol-1]
HARD
At 104.2°C, the vapour pressure of a solution of 7.5 g of a solute in 100 g of water is 740 mm of Hg and Kb=0.55, then the boiling point of the solution is ________
HARD
At 100oC the vapour pressure of a solution of 6.5 g of a non-volatile solute in 100 g water is 732 mm. If Kb=0.52 , the boiling point of this solution will be:
EASY
Two open beakers one containing a solvent and the other containing a mixture of that solvent with a non volatile solute are together sealed in a container. Over time:
HARD
224 mL of SO2(g) at 298 K and 1 atm is passed through 100 mL of 0.1 M NaOH solution. The non-volatile solute produced is dissolved in 36 g of water. The lowering of vapour pressure of solution (assuming the solution is dilute) (P°H2O=24 mm of Hg) is x×10-2 mm of Hg the value of x is                (Integer answer)
EASY
In 108 g of water, 18 g of a non-volatile compound is dissolved. At 100o C the vapor pressure of the solution is 750 mm Hg. Assuming that the compound does not undergo association or dissociation, the molar mass of the compound in g mol-1 is
EASY
Vapour pressure of water at 293 K is 17.535 mm Hg. Calculate the vapour pressure of water at 293 K when 25 g of glucose is dissolved in 450 g of water.
EASY
Which of the following statement is true?
EASY
The vapor pressure of a dilute solution of glucose is 750 mm of mercury at 373 K. The mole fraction of the solute is _________
HARD
Derive a relation between relative lowering of vapour pressure and mole fraction of the solute.
MEDIUM

5% solution of non-volatile solute in water has vapour pressure 745 mm of Hg at 373 K. Calculate the molar mass of the solute.

Given vapour pressure of pure water at 373 K is 760 mm of Hg

MEDIUM
Relative lowering of vapour pressure of a dilute solution of glucose dissolved in 1 kg of water is 0.002. The molality of the solution is
MEDIUM
18 g glucose C6H12O6 is added to 178.2 g water. The vapour pressure of water (in torr) for this aqueous solution is:
EASY
The mass of a non-volatile, non-electrolyte solute (molar mass = 50 g mol-1) needed to be dissolved in 114 g octane to reduce its vapour pressure by 75%, is: