A solution has 1 : 4 mole ratio of pentane to hexane. The vapour pressure of the pure hydrocarbons at 20oC are 440 mm of Hg for pentane and 120 mm of Hg for hexane. The mole fraction of pentane in the vapour phase would be
0.549
0.200
0.786
0.478
______________is not a colligative property.
Lowering of vapour pressure
Elevation in boiling point
Osmotic pressure
Freezing point
During osmosis, flow of water through a semi permeable membrane is
From solution having higher concentration only
From both sides of semi-permeable membrane with equal flow rates
From both sides of semi-permeable membrane with unequal flow rates
From solution having lower concentration only
A solution containing 10 g per dm3 of urea (molecular mass = 60 g mol-1) is isotonic with a 5% solution of a non-volatile solute is.
250 g mol-1
300 g mol-1
350 g mol-1
200 g mol-1
Molality is the most inconvenient way of expressing concentration because it_______________________
Has no unit
Is very difficult to find out
Involves difficult calculations
Involves the measurement of weight of liquids
The mole fraction of the solute in one molal aqueous solution is.
0.027
0.036
0.018
0.009
Which one is a colligative property?
Boiling point
Vapour pressure
The lowering of vapour pressure of the solvent takes place on dissolving a non-volatile solute because______________________
the surface tension of the solution decreases
the density of the solution increases
the molecules of the solvent on the surface are replaced by the molecules of the solute
the viscosity of the solution increases
The vapour pressure of benzene at a certain temperature is 640 mmHg. A non-volatile and non-electrolyte solid, Weighing 2. 175g is added to 39.08g of benzene. If the vapour pressure of the solution is 600 mmHg, what is the molecular weight of solid substance?
49.50
50.60
69.40
79.82
Which one of the following salts will have the same value of van't Hoff factor (i) as that of K4[Fe(CN)6]?
Al2(SO4)3
NaCI
AI(NO3)3
Na2SO4
