Date: 15-Jul-2025

Weakly Test Marks: 50

Time: 60
1. Which of the following formula CORRECTLY gives the value is 1.86 K kg mol–1.
of ebullioscopic constant?
(A)0.5 mol kg–1 (B)1 mol kg–1
(A) (B)
(C)2 mol kg–1 (D)3 mol kg–1

(C) (D) 10. The vapour pressure of solvent decreases by 10 mm Hg if

mole fraction of non-volatile solute is 0.2. Calculate vapour
pressure of solvent.
2. Calculate the freezing point depression of solvent when 20
(A)50 mm of Hg (B)40 mm of Hg
gram of nonvolatile solute with molar mass 60 g mol–1 is
dissolved in 1180 gram solvent. (Cryoscopic constant of (C)70 mm of Hg (D)60 mm of Hg
solvent is 1.18 K kg mol–1)
11. Molal depression constant for a liquid is 2.77 °C kg mol–1. In
(A)0.33 K (B)0.41 K (C)2.5 K (D)5.2 K Kelvin scale its value is _______.

3. Henry’s law is a relation between _______. (A)271.77 K kg mol–1 (B)275.77 K kg mol–1

(A)temperature and pressure (B)pressure and (C)2.77 K kg mol–1 (D)27.7 K kg mol–1
solubility
12. 15 × 10–4 kg urea dissolved in 1 lit of H2O and it is isotonic
(C)volume and solubility (D)pressure and volume with 500 mL aq. glucose solution. What is the amount of
4. Calculate osmotic pressure exerted by a solution containing glucose present in solution? (At. mass: C = 12, H = 1, O = 16,
0.822 g of solute in 300 mL of water at 300 K. (Molar mass of N = 14).

solute = 340 g mol–1, R = 0.0821 L atm mol–1 K–1) (A)4.60 g (B)1.8 g (C)3.45 g (D)2.25 g
(A)0.1 atm (B)0.2 atm (C)0.5 atm (D)0.4 atm 13. What is the molal elevation constant if one gram mole of a
nonvolatile solute is dissolved in 1 kg of ethyl acetate? (ΔTb
5. Calculate the molar mass of solute when 50 gram solute is
= xK)
dissolved in 150 gram solvent that boils at 84 ºC. (Kb for
solvent is 2.7 K kg mol–1 and boiling point of solvent is 75 ºC) (A)x K kg mol–1 (B) K kg mol–1

(A)134 g mol–1 (B)100 g mol–1

(C)2x K kg mol–1 (D)3x K kg mol–1
(C)236 g mol–1 (D)190 g mol–1
14. Calculate the molar mass of solute in a solution prepared by
6. 5 g sucrose (molar mass = 342) is dissolved in 100 g of dissolving 1 gram in 0.3 dm3 solvent having osmotic pressure
solvent, decreases the freezing point by 2.15 K. What is 0.2 atm at 300 K.
cryoscopic constant of solvent?

(A)14.7 K kg mol–1 (B)2.15 K kg mol–1 (A)442 g mol–1 (B)372 g mol–1

(C)4.30 K kg mol–1 (D)7.35 K kg mol–1 (C)390 g mol–1 (D)410 g mol–1

7. A solution of nonvolatile solute is obtained by dissolving 30 g 15. van’t Hoff factor for aqueous monofluoroacetic acid is
in 120 g solvent has boiling point elevation 7.2 K. What is the _______.
molar mass of solute if molal elevation constant of solvent is (A)i = 1 + 2 α (B)i = 1 – 2α
2.77 K kg mol­–1
­ ?
(C)i = 1 + α (D)i =1–α
(A)96.2 g mol­–1
­ (B)86.5 g mol­–1
­
16. Calculate osmotic pressure of 0.2 M aqueous KCl solution at
(C)105.4 g mol­–1
­ (D)112.6 g mol­–1
­ 0°C if van’t Hoff factor for KCl is 1.83. [R = 0.082 dm3 atm
8. The molal elevation constant is the ratio of elevation in boiling mol–1 K–1]
point to _______.
(A)8.2 atm (B)9.4 atm (C)10.6 atm (D)6.5 atm
(A)mole fraction of solute (B)molality of solution
17. Calculate the molar mass of nonvolatile solute when
(C)molarity of solution (D)normality of solution of it is dissolved in 600 g water at 30 °C. [Relative lowering
of vapour pressure = 0.03]
9. Calculate the molality of solution of nonvolatile solute if
(A)75 g mol–1 (B)100 g mol–1
depression in freezing point is 3.72 K and cryoscopic constant
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 (C)125 g mol–1 (D)150 g mol–1 (C)Boiling point of pure solvent is always greater than
boiling point of its solution containing a non-volatile
18. A solution of 5.6 g nonvolatile solute in 50 g solvent has
solute.
elevation in boiling point 1.75 K. What is the molar mass of
solute (Kb = 3 K kg mol–1)? (D)Vapour pressure of a solution containing a
(A)192 g mol–1 non-volatile solute is always greater than
(B)200 g mol–1
vapour pressure of pure solvent.
(C)184 g mol–1 (D)176 g mol–1
28. Which from the following statements is correct for aqueous
19. Identify the compound amongst the following of which 0.1 M solution of urea and of sucrose?
aqueous solution has highest boiling point.
[Molar mass of urea = 60 g mol–1 Molar mass of sucrose =
(A)Glucose (B)Sodium chloride
342 g mol–1]
(C)Calcium chloride (D)Ferric chloride
(A)Osmotic pressure exhibited by urea solution is lower
20. According to Raoult’s law, relative lowering of vapour than that of sucrose solution.
pressure for a solution containing a non-volatile solute is
(B)Urea solution is hypertonic to sucrose solution.
equal to:
(C)These solutions are isotonic.
(A)moles of solute.
(D)On doubling the concentration of sucrose solution it
(B)mole fraction of solute. becomes hypertonic to urea solution.
(C)moles of solvent. 29. What is vapour pressure of a solution containing 2.4 g urea in
(D)mole fraction of solvent. 10.8 g of water? ( = 400 mm Hg, atomic mass of: C = 12,

21. van’t Hoff factor of centimolal solution of K3[Fe(CN)6] is H = 1, O = 16, N = 14)

3.333. Calculate the percent dissociation of K3[Fe(CN)6]. (A)375 mm Hg (B)210 mm Hg

(A)33.33 (B)0.78 (C)78 (D)23.33 (C)160 mm Hg (D)260 mm Hg
22. Calculate the Henry's law constant at 25 °C if solubility of 30. What is the unit of molality?
gas in liquid is at 0.18 bar.
(A)mol kg–1 K(B)mol kg–1 (C)mol dm–3 (D)mol kg
(A)0.1166 mol dm–3 bar–1 (B)0.1445 mol dm–3 bar–1
31. Which of the following solutions on complete dissociation
(C)0.1730 mol dm–3 bar–1 (D)0.2014 mol dm–3 bar–1 exhibits maximum elevation in boiling point?

(A)0.1 m KCl (B)0.05 m NaCl

23. Which among the following salts dissolves in water with the
absorption of heat? (C)0.1 m BaCl2 (D)0.1 m MgSO4

(A)Na2SO4 (B)CaCl 32. 38.4 g of unknown substance (molar mass 384 g mol–1) and
2
116 g of acetone is used to prepare a solution at 313 K. If
(C)Li2SO4∙H2O (D)KCl
vapour pressure of pure acetone (molar mass 58 g mol–1) is
24. Find the molality of solution if boiling point increases by 1.75 0.842 atmosphere, what is the vapour pressure of solution?
K and molal elevation constant of solvent is 5 K kg mol–1. (A)0.7999 atm (B)0.880 atm
(A)0.55 m (B)0.81 m (C)0.35 m (D)0.70 m (C)0.958 atm (D)0.650 atm
25. Which of the following salts of same concentration will have
33. Which among the following solution has minimum freezing
same value of van’t Hoff factor as that of K4[Fe(CN)6]?
point depression assuming complete ionisation?
(A)MgSO4 (B)Na (C)Al2(SO4)3 (D)A(NO
2SO4 3)3 (A)0.1 m NaCl (B)0.2 m KNO3
26. What is mole fraction of solute in the solution if vapour
(C)0.1 m Na2SO4 (D)0.05 m CaCl2
pressure of pure solvent is 25.8 mm Hg and vapour pressure
of solution is 24.1 mm Hg at 30 °C? 34. Calculate the molar mass of solute when 1.5 gram non-
(A)0.036 (B)0.028 (C)0.066 (D)0.045 volatile solute dissolved in 100 mL solvent having density 0.8
g mL–1 lowers its freezing point by 0.75 K.
27. Identify the CORRECT statement from the following: (Freezing point depression constant for solvent is 5 K kg
(A)Vapour pressure of a solution containing a non-volatile mol–1)
solute is always less than vapour pressure of pure
(A)100 g mol–1 (B)125 g mol–1
solvent.
(C)110 g mol–1 (D)75 g mol–1
(B)Liquids having greater intermolecular forces
have lower boiling points.

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35. The van't Hoff factor (i) for a dilute aqueous solution of the mol–1)
strong electrolyte barium hydroxide is _______.
(A)15.7 mm Hg (B)21.6 mm Hg
(A)3 (B)0 (C)1 (D)2
(C)18.1 mm Hg (D)12.4 mm Hg
36. Which among the following values of concentration has same
values of ΔTb and Kb? 44. Calculate Henry’s law constant if solubility of nitrogen gas in

(A)1 m (B)1 (C) (D)1 water at 25°C is 6.85 × 10–4 mol dm–3.
M N
[Partial pressure of nitrogen gas = 0.9 bar]

(A)6.85 × 10–4 mol dm–3 bar–1

37. What is molar mass of solute if 50 gram of it in 150 gram
solvent has boiling point elevation of 5.54 K? (Kb = 2.77 K (B)4.71 × 10–4 mol dm–3 bar–1
kg mol–1)
(C)3.43 × 10–4 mol dm–3 bar–1
(A)180.0 g mol–1 (B)166.6 g mol–1
(D)7.6 × 10–4 mol dm–3 bar–1
(C)60.5 g mol–1 (D)90.3 g mol–1
45. Find the molar mass of solute when 2 gram dissolved in 60
38. Calculate the molar mass of solute when 2 gram solute gram benzene at 30°C and relative lowering of vapour
dissolved in 80 gram of the solvent elevates the boiling point pressure is 0.06. (Molar mass of benzene is 78 g mol–1)
by 0.5 K. (molar elevation constant of solvent is 3.5 K kg
(A)43.3 gram mol–1 (B)35.2 gram mol–1
mol–1)
(C)24.2 gram mol–1 (D)17.4 gram mol–1
(A)130 g mol–1 (B)175 g mol–1
46. A solution of nonvolatile solute is obtained by dissolving 15 g
(C)280 g mol–1 (D)300 g mol–1
in 200 mL water has depression in freezing point 0.75 K.
39. What is the molality of solution of a nonvolatile solute having Calculate the molar mass of solute if cryoscopic constant of
boiling point elevation 7.15 K and molal elevation constant water is 1.86 K kg mol–1.
–1
2.75 K kg mol ?
(A)160 g mol–1 (B)172 g mol–1
(A)3.2 m (B)2.0 m (C)2.6 m (D)3.8 m
(C)186 g mol–1 (D)198 g mol–1
40. Which of the following solutions will not show flow of
47. Which of the following solutions shows positive deviation
solvent in either direction when separated by semipermeable
from Raoult’s law?
membrane?

(A)6 g urea dm–3 and 85.5 g sucrose dm–3 (A)Ethanol + Acetone (B)Chloroform +
Acetone
(B)15 g urea dm–3 and 34.2 g sucrose dm–3
(C)Benzene + Toluene (D)Phenol + Aniline
(C)6 g urea dm–3 and 34.2 g sucrose dm–3
48. What is the unit of cryoscopic constant?
(D)15 g urea dm–3 and 171 g sucrose dm–3
(A)K kg mol (B)K kg mol–1
41. The solution containing 18 g dm–3 glucose (molar mass 180)
(C)K kg dm3 (D)K kg dm–3
in water and another containing 6 g dm–3 of solute A in water
boils at same temperature. What is molar mass of A? 49. Calculate the pressure of gas if the solubility of gas in water
(A)54 g mol–1 (B)90 g mol–1 at 25°C is 6.85 × 10–4 mol dm–3.
(Henry’s law constant is 6.85 × 10–4 mol dm–3 bar–1)
(C)120 g mol–1 (D)60 g mol–1
(A)1 bar (B)0.5 bar (C)1.5 bar (D)2.0 bar
42. Calculate the partial pressure of oxygen if its solubility in
water is 3.2 mg dm–3. 50. A 5% solution of cane sugar (molar mass 342) is isotonic
(KH = 2 × 10–3 mol dm–3 atm–1) with 1% solution of non-electrolyte substance X, the molar
mass of substance X is:
(A)0.03 atm (B)0.04 atm (C)0.05 atm (D)0.06 atm (A)34.2 g mol–1 (B)171.2 g mol–1
43. What is vapour pressure of a solution containing 6 g urea in
(C)136.8 g mol–1 (D)68.4 g mol–1
16.2 g of water? ( = 24 mm Hg, molar mass of urea = 60 g

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