Multiple Choice QuestionsBenzene and toluene form nearly ideal solutions. At 20o C, the vapour pressure of benzene is 75 torr and that of toluene is 22 torr. The partial vapour pressure of benzene at 20o C for a solution containing 78 g of benzene and 46 g of toluene in torr is
50
25
37.5
37.5
Two solutions of a substance (non-electrolyte) are mixed in the following manner. 480 ml of 1.5 M first solution + 520 mL of 1.2 M second solution. What is the molarity of the final mixture?
1.20 M
1.50 M
1.344 M
1.344 M
Equimolar solutions in the same solvent have
Same boiling point but different freezing point
Same freezing point but different boiling point
Same boiling and same freezing points
Same boiling and same freezing points
Which one of the following aqueous solutions will exhibit highest boiling point?
0.01 M Na2SO4
0.015 M glucose
0.015 M urea
0.015 M urea
6.02×1020 molecules of urea are present in 100 ml of its solution. The concentration of urea solution is
0.001 M
0.1 M
0.02 M
0.02 M
To neutralize completely 20 mL of 0.1 M aqueous solution of phosphorous acid (H3PO3), the volume of 0.1 M aqueous KOH solution required is
10 mL
60 mL
40 mL
40 mL
Which of the following liquid pairs shows a positive deviation from Raoult’s law?
Water – hydrochloric acid
Acetone – chloroform
Water – nitric acid
Water – nitric acid
Which one of the following statements is false?
Raoult’s law states that the vapour pressure of a components over a solution is proportional to its mole fraction
Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression
The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is BaCl2 > KCl > CH3COOH > sucrose
The correct order of osmotic pressure for 0.01 M aqueous solution of each compound is BaCl2 > KCl > CH3COOH > sucrose
B.
Two sucrose solutions of same molality prepared in different solvents will have the same freezing point depression
(a)pA = XA pAo : true
(b) ΔTf =Kfm
Kf is dependent on solvent
Thus is dependent on solvent
Thus freezing points [= t(solvent)- ΔTf) are different.
(c) i = [1 + (y-1) x]
y = number of ions
x = degree of ionisation
i = 3 for BaCl2 x = 1 (strong electrolyte)
i = 2 for KCl x = 1 (strong electrolyte)
i = (1+x) for CH3COOH x<i = (for BaCl2)>KCl>CH3COOH>Sucrose
(d) π = imRT = = MRT ; true (if van't Hoff factor i = 1
The molar solubility product is Ksp. ‘s’ is given in terms of Ksp by the relation
s = (256 Ksp)1/5
s = (256 Ksp)1/5
For 1 molal aqueous solution of the following compounds, which one will show the highest freezing point?
[Co(H2O)3 Cl3].3H2O
[Co(H2O)6]Cl3
[Co(H2O)5Cl] Cl2.H2O
[Co(H2O)4Cl2]Cl.2H2O
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