Q1. Which of the following is a colligative property?

a) Refractive index
b) Boiling point
c) Osmotic pressure
d) Viscosity
Answer: c

Q2. The concentration term affected by temperature is:

a) Molality
b) Molarity
c) Mole fraction
d) Mass %
Answer: b

Q3. The molality of a solution containing 5.8 g NaCl in 500 g water is:
a) 0.1 m
b) 0.2 m
c) 0.4 m
d) 1.0 m
Answer: b

Q4. Which of the following solutions will have the lowest freezing point?
a) 0.1 M NaCl
b) 0.1 M Glucose
c) 0.1 M CaCl₂
d) 0.1 M Urea
Answer: c

Q5. Which of the following represents an ideal solution?

a) H₂O + C₂H₅OH
b) Benzene + Toluene
c) Acetone + Chloroform
d) HCl + H₂O
Answer: b

Q6. Henry’s law constant (kH) depends on:

a) Pressure only
b) Solubility only
c) Temperature only
d) Temperature and gas type
Answer: d

Q7. Which of the following has maximum van’t Hoff factor (i)?
a) NaCl
b) K₂SO₄
c) Glucose
d) AlCl₃
Answer: d

Q8. Raoult’s law is applicable to:

a) Solids
b) Ideal gas
c) Ideal solution
d) Non-ideal solution
Answer: c

Q9. A positive deviation from Raoult’s law is shown by:

a) Acetone + Water
b) HCl + Water
c) Ethanol + Water
d) Benzene + Methanol
Answer: d

Q10. Molality of pure water is:

a) Zero
b) 55.5
c) Infinite
d) Cannot be defined
Answer: a

Q11. The unit of Henry’s law constant is:

a) atm
b) mol L⁻¹
c) mol kg⁻¹
d) atm mol⁻¹
Answer: a

Q12. The vapour pressure of a solution is always:

a) Higher than pure solvent
b) Lower than pure solvent
c) Equal to pure solvent
d) Independent of solute
Answer: b

Q13. Which will show highest elevation in boiling point?

a) 1 M Glucose
b) 1 M NaCl
c) 1 M MgCl₂
d) 1 M Urea
Answer: c

Q14. Which concentration term is independent of temperature?

a) Molarity
b) Normality
c) Molality
d) Volume %
Answer: c

Q15. Which is not a unit of concentration?

a) ppm
b) Normality
c) Density
d) Mole fraction
Answer: c

Q16. Azeotropes are:

a) Pure liquids
b) Constant boiling mixtures
c) Non-volatile liquids
d) Saturated solutions
Answer: b

Q17. The boiling point of water increases with addition of:

a) Glucose
b) NaCl
c) Alcohol
d) Both a and b
Answer: d

Q18. The expression π = CRT is used to calculate:

a) Boiling point
b) Vapour pressure
c) Osmotic pressure
d) Freezing point
Answer: c

Q19. Which of the following is true for non-ideal solutions?

a) Obey Raoult’s law
b) Have no enthalpy change
c) Show positive or negative deviation
d) Always form azeotropes
Answer: c

Q20. Which solution will freeze at the lowest temperature?

a) 0.2 M Glucose
b) 0.2 M NaCl
c) 0.2 M BaCl₂
d) 0.2 M KCl
Answer: c

Q21. Which condition favours ideal behaviour in solutions?

a) Weak solute-solvent interaction

b) Strong solute-solvent interaction
c) Identical size of molecules
d) High temperature
Answer: c

Q22. Elevation in boiling point is proportional to:

a) Normality
b) Molality
c) Molarity
d) Density
Answer: b

Q23. Which does not affect vapour pressure of solvent in a solution?

a) Temperature
b) Nature of solvent
c) Non-volatile solute
d) Volume of solute
Answer: d

Q24. Van’t Hoff factor (i) for C₆H₁₂O₆ (glucose) is:

a) 1
b) 0
c) 2
d) 3
Answer: a

Q25. The solution which forms maximum boiling azeotrope is:

a) Acetone + Benzene
b) Ethanol + Water
c) HNO₃ + Water
d) Chloroform + Acetone
Answer: b

Q26. Which gas will have lowest solubility in water?

a) NH₃
b) CO₂
c) H₂
d) SO₂
Answer: c

Q27. Freezing point depression is directly proportional to:

a) Mole fraction of solute
b) Molarity
c) Molality
d) Normality
Answer: c

Q28. Which of these has maximum freezing point depression?

a) 0.1 m glucose
b) 0.1 m NaCl
c) 0.1 m K₂SO₄
d) 0.1 m BaCl₂
Answer: d

Q29. A solution obeys Raoult’s law when:

a) ΔHmix = 0
b) ΔVmix = 0
c) Both a and b
d) None
Answer: c
Q30. In a solution, mole fraction of solvent is 0.7, solute is:
a) 0.7
b) 0.3
c) 1
d) Cannot be determined
Answer: b

Q31. Which of the following is not a colligative property?

a) Osmotic pressure
b) Elevation in boiling point
c) Freezing point depression
d) pH
Answer: d

Q32. What is the effect of increasing temperature on Henry’s constant?

a) Increases
b) Decreases
c) No change
d) Becomes zero
Answer: a

Q33. If a solution has two volatile components, total vapour pressure is:
a) Sum of partial pressures
b) Average of partial pressures
c) Always less than both
d) Independent of mole fraction
Answer: a

Q34. Which solution behaves non-ideally with negative deviation?

a) Acetone + Carbon tetrachloride
b) Acetone + Chloroform
c) Benzene + Toluene
d) Ethanol + Methanol
Answer: b

Q35. Which gas follows Henry’s law least?

a) He
b) N₂
c) CO₂
d) NH₃
Answer: d

Q36. A solute which undergoes dimerization in solution shows:

a) i < 1
b) i > 1
c) i = 1
d) i = 0
Answer: a
Q37. In osmosis, solvent moves from:
a) Low to high solute concentration
b) High to low solute concentration
c) Low pressure to high pressure
d) High to low vapour pressure
Answer: a

Q38. Which one has minimum van’t Hoff factor (i)?

a) KCl
b) Glucose
c) AlCl₃
d) MgCl₂
Answer: b

Q39. Which of the following is most ideal solution?

a) Benzene + Toluene
b) Acetone + Water
c) Acetone + Chloroform
d) HCl + Water
Answer: a

Q40. In an ideal solution, the enthalpy change is:

a) Positive
b) Negative
c) Zero
d) Infinite
Answer: c

Q41. Which property does not depend on number of solute particles?

a) Boiling point elevation
b) Freezing point depression
c) Vapour pressure lowering
d) Refractive index
Answer: d

Q42. If two liquids form a solution with volume contraction, it is:

a) Ideal
b) Non-ideal positive deviation
c) Non-ideal negative deviation
d) Colloidal
Answer: c

Q43. Which expression defines Henry’s law?

a) p = KHx
b) p = KH/m
c) p = x/KH
d) x = pKH
Answer: a

Q44. Which colligative property is preferred for molar mass determination of biomolecules?
a) Freezing point depression
b) Boiling point elevation
c) Vapour pressure lowering
d) Osmotic pressure
Answer: d

Q45. A 0.5 molal solution of KCl freezes at:

a) Lower than water
b) Higher than water
c) Same as water
d) Boils instead
Answer: a

Q46. In Raoult’s law, p° represents:

a) Partial pressure of solvent
b) Vapour pressure of pure solvent
c) Vapour pressure of solute
d) Osmotic pressure
Answer: b

Q47. Addition of non-volatile solute to liquid:

a) Increases vapour pressure
b) Decreases vapour pressure
c) Does not change it
d) Makes it volatile
Answer: b

Q48. Which solution shows maximum osmotic pressure?

a) 1 M glucose
b) 1 M NaCl
c) 1 M MgCl₂
d) 1 M BaSO₄
Answer: c

Q49. What is the unit of osmotic pressure?

a) atm
b) m⁻¹
c) mol L⁻¹
d) Pascal
Answer: a

Q50. What is the molality of 1 mol solute in 500 g solvent?

a) 1
b) 2
c) 0.5
d) 0.25
Answer: b

Q51. In hypertonic solution, a cell will:

a) Gain water
b) Swell
c) Shrink
d) Burst
Answer: c

Q52. The relation between ∆Tf and Kf is:

a) ∆Tf = Kf × molality
b) ∆Tf = molality / Kf
c) ∆Tf = Kf / molality
d) ∆Tf = Kf × molarity
Answer: a

Q53. Which solution is isotonic to 0.1 M NaCl?

a) 0.1 M glucose
b) 0.05 M Na₂SO₄
c) 0.1 M CaCl₂
d) 0.05 M MgCl₂
Answer: b

Q54. Henry’s law constant for a gas is high. Its solubility is:
a) Low
b) High
c) Infinite
d) Zero
Answer: a

Q55. What is van’t Hoff factor for AlCl₃?

a) 2
b) 3
c) 4
d) 1
Answer: c

Q56. Azeotropes cannot be separated by:

a) Filtration
b) Fractional distillation
c) Crystallization
d) Sublimation
Answer: b

Q57. Which one forms minimum boiling azeotrope?

a) Water + HCl
b) Ethanol + Water
c) Acetone + Chloroform
d) Benzene + Toluene
Answer: c

Q58. Cryoscopic constant Kf depends on:

a) Solute
b) Temperature
c) Solvent
d) Pressure
Answer: c
Q59. Which graph best represents Henry’s law?
a) p vs x is linear
b) p vs 1/x is linear
c) p vs x is parabolic
d) p vs T is linear
Answer: a

Q60. The freezing point of water is lowered by adding:

a) Urea
b) NaCl
c) Glucose
d) All of these
Answer: d

Q61. Which solution will have the highest boiling point?

a) 0.1 M urea
b) 0.1 M glucose
c) 0.1 M NaCl
d) 0.1 M MgCl₂
Answer: d

Q62. The van’t Hoff factor for K₂SO₄ is:

a) 1
b) 2
c) 3
d) 4
Answer: c

Q63. Which of the following shows negative deviation from Raoult’s law?
a) Acetone + Water
b) Chloroform + Acetone
c) Ethanol + Methanol
d) Benzene + Toluene
Answer: b

Q64. Which of these will not affect colligative properties?

a) Number of solute particles
b) Nature of solute
c) Temperature
d) Mass of solute
Answer: b

Q65. When two liquids are completely miscible and obey Raoult’s law, the solution is:
a) Ideal
b) Azeotropic
c) Non-ideal
d) Heterogeneous
Answer: a

Q66. The boiling point of pure solvent is 373 K. In presence of non-volatile solute, it becomes:
a) 373 K
b) >373 K
c) <373 K
d) 0 K
Answer: b

Q67. Which property is used in reverse osmosis water purification?

a) Boiling point
b) Vapour pressure
c) Osmotic pressure
d) Surface tension
Answer: c

Q68. When vapour pressure of solution is lower than pure solvent, it shows:
a) Boiling point depression
b) Boiling point elevation
c) No change
d) Decomposition
Answer: b

Q69. Which is an example of an ideal solution?

a) Benzene + Toluene
b) Ethanol + Water
c) Acetone + Chloroform
d) H₂O + HCl
Answer: a

Q70. Freezing point depression is a:

a) Colligative property
b) Chemical change
c) Molar property
d) None of these
Answer: a

Q71. At constant temperature, solubility of a gas is directly proportional to:

a) Vapour pressure
b) Volume
c) Partial pressure
d) Boiling point
Answer: c

Q72. Which condition leads to maximum solubility of gases in liquids?

a) High pressure, low temperature
b) High pressure, high temperature
c) Low pressure, high temperature
d) Low pressure, low temperature
Answer: a

Q73. Reverse osmosis can be reversed by applying pressure:

a) Less than osmotic pressure
b) Equal to osmotic pressure
c) Greater than osmotic pressure
d) Zero
Answer: c
Q74. In blood cells, hypotonic solution causes:
a) Shrinkage
b) Bursting
c) No change
d) Crystallization
Answer: b

Q75. Which of these depends only on number of solute particles?

a) Osmotic pressure
b) Viscosity
c) Conductance
d) Surface tension
Answer: a

Q76. Van’t Hoff factor becomes less than expected when solute:
a) Ionizes
b) Associates
c) Dissolves
d) Crystallizes
Answer: b

Q77. The freezing point of 0.1 m solution is:

a) Lower than pure solvent
b) Higher than pure solvent
c) Same as solvent
d) Depends on solute
Answer: a

Q78. The boiling point of a solution is always:

a) Higher than solvent
b) Lower than solvent
c) Equal to solvent
d) Unpredictable
Answer: a

Q79. In osmosis, solvent always moves from:

a) Low to high solute concentration
b) High to low solute concentration
c) High to low osmotic pressure
d) Solid to liquid
Answer: a

Q80. Which property distinguishes an electrolyte from non-electrolyte in colligative effects?

a) Molarity
b) Boiling point
c) Van’t Hoff factor
d) Density
Answer: c
Q81. Which one has the maximum number of particles in 1 L solution?
a) 1 M NaCl
b) 1 M AlCl₃
c) 1 M glucose
d) 1 M BaCl₂
Answer: b

Q82. Which one does NOT form an ideal solution?

a) Ethyl alcohol + Water
b) n-Hexane + n-Heptane
c) Benzene + Toluene
d) CCl₄ + SiCl₄
Answer: a

Q83. Which condition favours maximum freezing point depression?

a) Dilute solution
b) Concentrated solution
c) High molecular weight solute
d) Low molecular weight solute
Answer: d

Q84. Van’t Hoff factor for Na₂SO₄ assuming 100% dissociation is:
a) 1
b) 2
c) 3
d) 4
Answer: c

Q85. Cryoscopic constant Kf has unit:

a) K mol⁻¹
b) K kg mol⁻¹
c) mol K⁻¹
d) kg mol⁻¹
Answer: b

Q86. What is the ideal value of i (van’t Hoff factor) for 1 M sucrose?
a) 0
b) 1
c) 2
d) 3
Answer: b

Q87. Which of the following shows positive deviation from Raoult’s law?
a) Acetone + Water
b) Benzene + Toluene
c) HNO₃ + Water
d) Chloroform + Acetone
Answer: a

Q88. The boiling point of azeotropes is:

a) Minimum
b) Constant
c) Maximum
d) Variable
Answer: b

Q89. Freezing point of a solution is −1.86°C. If Kf = 1.86 K kg/mol, what is molality?

a) 1
b) 2
c) 0.5
d) 3
Answer: a

Q90. Which type of solution obeys Henry’s law?

a) Gas-liquid
b) Liquid-solid
c) Solid-gas
d) Liquid-liquid
Answer: a

Q91. In case of positive deviation, total pressure is:

a) Lower than expected
b) Higher than expected
c) Equal
d) Zero
Answer: b

Q92. Depression in freezing point is directly proportional to:

a) Molarity
b) Molality
c) Density
d) Volume
Answer: b

Q93. Osmosis is spontaneous flow of solvent through:

a) Permeable membrane
b) Impermeable membrane
c) Semi-permeable membrane
d) Non-permeable wall
Answer: c

Q94. Which of the following is not a colligative property?

a) Boiling point elevation
b) Vapour pressure lowering
c) pH
d) Freezing point depression
Answer: c

Q95. Which of the following liquids pair is most likely to form a maximum boiling azeotrope?
a) Acetone + CS₂
b) HNO₃ + H₂O
c) Ethanol + Water
d) Chloroform + Acetone
Answer: b

Q96. Which solution has the lowest vapour pressure?

a) Pure solvent
b) 1 M NaCl
c) 1 M glucose
d) 1 M MgCl₂
Answer: d

Q97. Which statement is true for an ideal solution?

a) ∆H = 0 and ∆V = 0
b) ∆H = 0 and ∆V ≠ 0
c) ∆H ≠ 0 and ∆V = 0
d) ∆H ≠ 0 and ∆V ≠ 0
Answer: a

Q98. The solubility of CO₂ in soft drinks is governed by:

a) Dalton’s law
b) Henry’s law
c) Raoult’s law
d) Boyle’s law
Answer: b

Q99. Which of the following affects osmotic pressure most?

a) Temperature
b) Size of molecule
c) Number of particles
d) Density
Answer: c

Q100. The highest freezing point is shown by:

a) 0.1 m NaCl
b) 0.1 m MgCl₂
c) 0.1 m glucose
d) 0.1 m AlCl₃
Answer: c

Q101. Calculate the molality of a solution prepared by dissolving 5 g of NaOH (M = 40 g/mol) in 250 g of
water.
Answer:
Moles of NaOH = 5/40 = 0.125 mol
Mass of solvent (kg) = 250/1000 = 0.25 kg
Molality = 0.125 / 0.25 = 0.5 mol/kg

Q102. Calculate the mole fraction of glucose in a solution containing 180 g of glucose (M = 180 g/mol) in 900
g of water.
Answer:
Moles of glucose = 180/180 = 1 mol
Moles of water = 900/18 = 50 mol
Mole fraction of glucose = 1 / (1 + 50) = 0.0196

Q103. A 1 molal solution of a non-volatile solute is prepared in water. Calculate the depression in freezing
point. (Kf = 1.86 K·kg/mol)
Answer:
ΔTf = i × Kf × m = 1 × 1.86 × 1 = 1.86 K

Q104. A solution of urea (M = 60 g/mol) containing 3 g in 100 g of water. Calculate the lowering of vapour
pressure if vapour pressure of pure water is 25 mmHg.
Answer:
Moles of urea = 3/60 = 0.05 mol
Moles of water = 100/18 = 5.56 mol
Mole fraction of solute = 0.05 / (0.05 + 5.56) ≈ 0.0089
Relative lowering = 0.0089
Lowering = 25 × 0.0089 = 0.2225 mmHg

Q105. Calculate osmotic pressure of 0.2 M glucose solution at 27°C. (R = 0.0821 L·atm/mol·K)
Answer:
T = 273 + 27 = 300 K
π = CRT = 0.2 × 0.0821 × 300 = 4.926 atm

Q106. Find molar mass of solute if 2 g of it is dissolved in 100 g benzene (Kf = 5.12) and freezing point is
lowered by 0.64°C.
Answer:
Molality = ΔTf / Kf = 0.64 / 5.12 = 0.125 m
Mol of solute = molality × mass of solvent (kg) = 0.125 × 0.1 = 0.0125 mol
Molar mass = 2 / 0.0125 = 160 g/mol

Q107. A solution is prepared by dissolving 6 g of urea (M = 60 g/mol) in 90 g of water. Calculate the relative
lowering of vapour pressure.
Answer:
Moles of urea = 6 / 60 = 0.1 mol
Moles of water = 90 / 18 = 5 mol
Relative lowering = 0.1 / (0.1 + 5) = 0.0196

Q108. Calculate mass of NaCl (M = 58.5 g/mol) required to be dissolved in 500 g of water to lower freezing
point by 3.72°C. (Kf = 1.86)
Answer:
ΔTf = iKf m = 2 × 1.86 × m = 3.72
m = 3.72 / (2 × 1.86) = 1 mol/kg
Mol = 1 × 0.5 = 0.5 mol
Mass = 0.5 × 58.5 = 29.25 g

Q109. Calculate vapour pressure of water in a solution of 18 g glucose (M = 180 g/mol) in 180 g water.
(Vapour pressure of water = 760 mmHg)
Answer:
Moles glucose = 0.1 mol; Moles water = 10 mol
Mole fraction of water = 10 / (10 + 0.1) = 0.9901
Vapour pressure = 760 × 0.9901 = 752.47 mmHg

Q110. Calculate molar mass of solute when 1 g of it in 100 g of water causes osmotic pressure of 0.3 atm at
27°C.
Answer:
π = CRT → 0.3 = (1/M) × (1000/1000) × 0.0821 × 300
M = (1 × 0.0821 × 300) / 0.3 = 82.1 g/mol

Q111. Calculate boiling point of 0.5 molal KCl solution. (Kb = 0.52 K·kg/mol, water b.p. = 373 K)
Answer:
i = 2 (for KCl), ΔTb = iKb m = 2 × 0.52 × 0.5 = 0.52 K
Boiling point = 373 + 0.52 = 373.52 K

Q112. 5.85 g of NaCl is dissolved in 500 g of water. Calculate molality.

Answer:
Moles NaCl = 5.85 / 58.5 = 0.1 mol
Molality = 0.1 / 0.5 = 0.2 mol/kg

Q113. What is the freezing point of 0.1 molal solution of glucose in water? (Kf = 1.86)
Answer:
ΔTf = 1.86 × 0.1 = 0.186 K
Freezing point = 273 - 0.186 = 272.814 K

Q114. Calculate osmotic pressure of 0.01 M NaCl solution at 37°C (i = 2).

Answer:
π = iCRT = 2 × 0.01 × 0.0821 × 310 = 0.509 atm
Q115. 0.2 mol of non-volatile solute is dissolved in 1 kg of solvent. What is depression in freezing point? (Kf =
1.86)
Answer:
ΔTf = 1.86 × 0.2 = 0.372 K

Q116. A solution shows 2 atm osmotic pressure at 300 K. Calculate concentration of solute.
Answer:
π = CRT → C = π / (RT) = 2 / (0.0821 × 300) = 0.0812 M

Q117. Freezing point depression is 1.24 K, Kf = 1.86. Find molality.

Answer:
m = ΔTf / Kf = 1.24 / 1.86 = 0.666 mol/kg

Q118. 50 g of ethylene glycol (M = 62) is dissolved in 200 g of water. Calculate freezing point depression.
Answer:
Mol = 50 / 62 = 0.806 mol
Molality = 0.806 / 0.2 = 4.03 m
ΔTf = 1.86 × 4.03 = 7.49 K

Q119. Calculate molar mass if 0.5 g of solute gives osmotic pressure of 1 atm in 100 mL at 298 K.
Answer:
π = CRT → 1 = (0.5/M) × (1) × 0.0821 × 298
M = 0.5 × 0.0821 × 298 = 12.24 g/mol

Q120. Boiling point elevation is 0.52°C for 1 molal solution. What is Kb?
Answer:
ΔTb = Kb × m → Kb = 0.52 / 1 = 0.52 K·kg/mol

Q121. 3.6 g of acetic acid (CH₃COOH, M = 60 g/mol) is dissolved in 100 g of benzene. Calculate molality.
Answer:
Mol = 3.6 / 60 = 0.06 mol
Mass solvent = 0.1 kg
Molality = 0.06 / 0.1 = 0.6 mol/kg

Q122. 5.4 g of AlCl₃ (M = 133.5) is dissolved in 200 g of water. Find molality.

Answer:
Mol = 5.4 / 133.5 = 0.0405 mol
Molality = 0.0405 / 0.2 = 0.2025 mol/kg
Q123. Calculate boiling point of 0.2 molal NaCl solution. (Kb = 0.52 K·kg/mol, i = 2)
Answer:
ΔTb = i × Kb × m = 2 × 0.52 × 0.2 = 0.208 K
Boiling point = 373 + 0.208 = 373.208 K

Q124. A 0.25 molal solution of a non-electrolyte is prepared in water. Calculate its freezing point.
Answer:
ΔTf = 1.86 × 0.25 = 0.465
Freezing point = 273 - 0.465 = 272.535 K

Q125. Calculate the mass of glucose (M = 180 g/mol) needed to make 500 mL of 0.5 M solution
Answer:
Mol = M × V = 0.5 × 0.5 = 0.25 mol
Mass = 0.25 × 180 = 45 g

Q126. Osmotic pressure of 1.5 M NaCl solution at 27°C (assume i = 2).

Answer:
π = iCRT = 2 × 1.5 × 0.0821 × 300 = 73.89 atm

Q127. Calculate vapour pressure of water in solution with 18 g glucose in 180 g water. (P° = 25 mmHg)
Answer:
Moles glucose = 0.1 mol; Moles water = 10 mol
Mole fraction of water = 10 / (10 + 0.1) = 0.9901
p = 25 × 0.9901 = 24.75 mmHg

Q128. 9 g of solute in 100 g water depresses freezing point by 0.93°C. Kf = 1.86. Find molar mass.
Answer:
Molality = 0.93 / 1.86 = 0.5
Moles = 0.5 × 0.1 = 0.05 mol
Molar mass = 9 / 0.05 = 180 g/mol

Q129. Calculate osmotic pressure of 0.2 M solution at 25°C.

Answer:
π = 0.2 × 0.0821 × 298 = 4.89 atm
Q130. 4.4 g of CO₂ is dissolved in 1 L of water. Calculate molarity. (M = 44 g/mol)
Answer:
Mol = 4.4 / 44 = 0.1 mol
Molarity = 0.1 mol/L = 0.1 M

Q131. Determine molar mass if osmotic pressure is 5 atm at 300 K for 1 g solute in 100 mL.
Answer:
π = CRT → 5 = (1/M) × 1 × 0.0821 × 300
M = (1 × 0.0821 × 300) / 5 = 4.926 g/mol

Q132. Calculate elevation in boiling point for 0.1 molal urea solution. (Kb = 0.52)
Answer:
ΔTb = 0.52 × 0.1 = 0.052 K

Q133. What is the freezing point of 1.5 molal urea in water? (Kf = 1.86)
Answer:
ΔTf = 1.5 × 1.86 = 2.79
Freezing point = 273 - 2.79 = 270.21 K

Q134. 2 g of unknown solute in 100 mL water gives osmotic pressure of 2.46 atm at 300 K. Find molar mass.
Answer:
π = CRT → 2.46 = (2/M) × 1 × 0.0821 × 300
M = (2 × 0.0821 × 300) / 2.46 = 20 g/mol

Q135. 0.01 molal NaCl solution has what osmotic pressure at 25°C? (i = 2)
Answer:
π = 2 × 0.01 × 0.0821 × 298 = 0.489 atm

Q136. Calculate molar mass of solute if 1.5 g in 250 mL has osmotic pressure of 2 atm at 300 K.
Answer:
π = CRT → 2 = (1.5/M) × 4 × 0.0821 × 300
M = (1.5 × 0.0821 × 4 × 300) / 2 = 73.89 g/mol

Q137. What mass of NaCl (i = 2) is needed to lower freezing point by 1.86°C of 1 kg water? (Kf = 1.86)
Answer:
ΔTf = iKf m → m = ΔTf / (iKf) = 1.86 / (2 × 1.86) = 0.5
Mol = 0.5 mol; Mass = 0.5 × 58.5 = 29.25 g
Q138. A 0.1 molal NaCl solution freezes at 271.88 K. What is Kf? (i = 2)
Answer:
ΔTf = 273 - 271.88 = 1.12
Kf = ΔTf / (i × m) = 1.12 / (2 × 0.1) = 5.6 K·kg/mol

Q139. 0.5 mol of glucose in 1.5 L solution at 298 K. Find osmotic pressure.
Answer:
π = (0.5 / 1.5) × 0.0821 × 298 = 8.15 atm

Q140. Freezing point of 1 molal solution of NaCl. (Kf = 1.86, i = 2)

Answer:
ΔTf = 2 × 1.86 × 1 = 3.72
Freezing point = 273 - 3.72 = 269.28 K

Q141. 2 molal KNO₃ solution, find elevation in boiling point (Kb = 0.52, i = 2)
Answer:
ΔTb = i × Kb × m = 2 × 0.52 × 2 = 2.08 K

Q142. Vapour pressure of water = 25 mmHg. What is vapour pressure of 0.2 molal glucose solution?
Answer:
Mole water = 55.56 mol; Mole glucose = 0.2
Mole fraction water ≈ 55.56 / (55.56 + 0.2) ≈ 0.9964
p = 25 × 0.9964 = 24.91 mmHg

Q143. What mass of ethylene glycol (M = 62) must be added to 1 kg water to decrease freezing point by
3.72°C? (Kf = 1.86)
Answer:
Molality = 3.72 / 1.86 = 2
Moles = 2; Mass = 2 × 62 = 124 g

Q144. Osmotic pressure of 0.25 M KCl at 30°C. (i = 2)

Answer:
π = 2 × 0.25 × 0.0821 × 303 = 12.45 atm
Q145. Calculate molarity if 9.8 g H₂SO₄ (M = 98) is dissolved in 500 mL.
Answer:
Mol = 9.8 / 98 = 0.1 mol; M = 0.1 / 0.5 = 0.2 M

Q146. What is the freezing point of solution containing 0.1 mol of Na₂SO₄ in 1 kg water? (Kf = 1.86, i = 3)
Answer:
ΔTf = i × Kf × m = 3 × 1.86 × 0.1 = 0.558
Freezing point = 273 - 0.558 = 272.442 K

Q147. 4 g urea in 100 g water gives osmotic pressure 1.23 atm at 27°C. Find molar mass.
Answer:
π = CRT → 1.23 = (4/M) × 0.0821 × 300
M = (4 × 0.0821 × 300) / 1.23 = 80 g/mol

Q148. Find freezing point of 0.1 molal CaCl₂ solution. (Kf = 1.86, i = 3)
Answer:
ΔTf = 3 × 1.86 × 0.1 = 0.558
Freezing point = 273 - 0.558 = 272.442 K

Q149. 180 g glucose in 1 L gives what osmotic pressure at 300 K?

Answer:
Mol = 1 mol; π = 1 × 0.0821 × 300 = 24.63 atm

Q150. 100 mL 1 M NaCl is diluted to 500 mL. What is new molarity?

Answer:
M₁V₁ = M₂V₂ → 1 × 100 = M₂ × 500 → M₂ = 0.2 M

SECTION C: ASSERTION & REASON QUESTIONS (Q151–200)

(Marking Scheme: A - Both Assertion and Reason are true, and Reason is the correct explanation; B - Both
true, but Reason is not the correct explanation; C - Assertion is true, Reason is false; D - Assertion is false,
Reason is true)

Q151.
Assertion: A solution shows a lower vapour pressure than the pure solvent.
Reason: Presence of solute decreases the escaping tendency of solvent molecules.
Answer: A
Q152.
Assertion: Molality is independent of temperature.
Reason: Molality is based on mass, which does not change with temperature.
Answer: A

Q153.
Assertion: Molarity of a solution changes with temperature.
Reason: Volume expands or contracts with temperature change.
Answer: A

Q154.
Assertion: Elevation in boiling point depends on the nature of solute.
Reason: Strong electrolytes ionise and produce more particles.
Answer: A

Q155.
Assertion: Glucose does not affect colligative properties as much as NaCl.
Reason: NaCl dissociates into ions, increasing particle number.
Answer: A

Q156.
Assertion: Boiling point of water increases on adding salt.
Reason: Addition of non-volatile solute lowers vapour pressure.
Answer: A

Q157.
Assertion: Freezing point depression is directly proportional to molality.
Reason: It is a colligative property and depends only on number of solute particles.
Answer: A

Q158.
Assertion: In ideal solutions, ΔHmixing = 0.
Reason: There are no intermolecular force changes in ideal mixing.
Answer: A
Q159.
Assertion: In a non-ideal solution, azeotrope formation can occur.
Reason: Azeotropes have either maximum or minimum boiling points.
Answer: A

Q160.
Assertion: Henry’s law constant increases with temperature.
Reason: Solubility of gas increases with temperature.
Answer: C

Q161.
Assertion: In case of hypertonic solution, water flows out of cell.
Reason: Osmosis drives solvent from lower to higher solute concentration.
Answer: A

Q162.
Assertion: Adding sugar to water lowers its vapour pressure.
Reason: Non-volatile solutes occupy surface area and reduce escaping tendency.
Answer: A

Q163.
Assertion: Van’t Hoff factor for Na₂SO₄ is 3.
Reason: It dissociates into 2Na⁺ and SO₄²⁻ ions.
Answer: A

Q164.
Assertion: 1 molal NaCl solution shows more freezing point depression than 1 molal glucose.
Reason: NaCl dissociates to produce more particles than glucose.
Answer: A

Q165.
Assertion: Reverse osmosis is used for water purification.
Reason: It applies pressure higher than osmotic pressure to force solvent across semipermeable membrane.
Answer: A

Q166.
Assertion: Colligative properties depend on amount, not type of solute.
Reason: Only number of solute particles in solution matters.
Answer: A

Q167.
Assertion: Elevation in boiling point is observed in electrolyte solutions.
Reason: Electrolytes increase number of solute particles.
Answer: A

Q168.
Assertion: For non-ideal solutions, Raoult’s law is not strictly applicable.
Reason: Deviations occur due to changes in intermolecular interactions.
Answer: A

Q169.
Assertion: NaCl is an ideal solute.
Reason: It dissociates completely in water.
Answer: B

Q170.
Assertion: Osmotic pressure increases with dilution.
Reason: Osmotic pressure is directly proportional to solute concentration.
Answer: D

Q171.
Assertion: A 0.1 molal BaCl₂ solution will have more freezing point depression than NaCl.
Reason: BaCl₂ gives three ions per formula unit.
Answer: A

Q172.
Assertion: Molarity is affected by temperature, molality is not.
Reason: Molarity depends on volume which changes with temperature.
Answer: A

Q173.
Assertion: Vapour pressure of water decreases when common salt is added.
Reason: Salt particles block water molecules from escaping into vapour phase.
Answer: A
Q174.
Assertion: Lowering of vapour pressure is proportional to mole fraction of solute.
Reason: According to Raoult’s law, vapour pressure lowers linearly with addition of solute.
Answer: A

Q175.
Assertion: The freezing point of solution is always lower than that of pure solvent.
Reason: Solute particles obstruct crystal formation during freezing.
Answer: A

Q176.
Assertion: Presence of solute increases boiling point of solvent.
Reason: It raises the temperature required to equal atmospheric pressure.
Answer: A

Q177.
Assertion: Osmosis is a spontaneous process.
Reason: It occurs from lower to higher solute concentration naturally.
Answer: A

Q178.
Assertion: Azeotropes show constant boiling composition.
Reason: Their liquid and vapour phases have same composition.
Answer: A

Q179.
Assertion: Elevation in boiling point is more in ionic solutes.
Reason: Ionic compounds give more number of particles.
Answer: A

Q180.
Assertion: Molality and mole fraction remain unchanged with temperature.
Reason: They are mass-based concentration units.
Answer: A
Q181.
Assertion: For 1 molal urea and 1 molal NaCl, osmotic pressure is more for NaCl.
Reason: NaCl produces more number of particles.
Answer: A

Q182.
Assertion: Glucose solution has lower vapour pressure than water.
Reason: Solute particles reduce escaping tendency of water molecules.
Answer: A

Q183.
Assertion: Raoult’s law is applicable to ideal solutions only.
Reason: Ideal solutions follow linear relationship of pressure and composition.
Answer: A

Q184.
Assertion: Addition of volatile solute increases vapour pressure.
Reason: It increases the total number of particles in vapour phase.
Answer: A

Q185.
Assertion: Osmotic pressure is a colligative property.
Reason: It depends only on number of solute particles, not their nature.
Answer: A

Q186.
Assertion: Lowering of vapour pressure is a colligative property.
Reason: It depends on the nature of solute.
Answer: C

Q187.
Assertion: 0.1 molal NaCl solution shows greater osmotic pressure than 0.1 molal urea.
Reason: NaCl dissociates to give more particles.
Answer: A

Q188.
Assertion: Reverse osmosis removes ions and impurities.
Reason: Pressure higher than osmotic pressure forces water through membrane.
Answer: A

Q189.
Assertion: The osmotic pressure of a 1 M solution is greater at higher temperature.
Reason: Osmotic pressure is directly proportional to temperature.
Answer: A

Q190.
Assertion: Colligative properties are not affected by electrolyte dissociation.
Reason: Electrolyte dissociation increases number of solute particles.
Answer: C

Q191.
Assertion: Ethanol-water mixture shows positive deviation from Raoult’s law.
Reason: A–B interactions are weaker than A–A and B–B interactions.
Answer: A

Q192.
Assertion: NaCl shows greater effect on colligative properties than glucose.
Reason: Ionic compounds give multiple particles per formula unit.
Answer: A

Q193.
Assertion: Vapour pressure is independent of external pressure.
Reason: It depends on temperature and intermolecular forces.
Answer: A

Q194.
Assertion: Isotonic solutions have same osmotic pressure.
Reason: They have same solute concentration.
Answer: A

Q195.
Assertion: The freezing point of water decreases when alcohol is added.
Reason: Alcohol is volatile and adds more particles.
Answer: A
Q196.
Assertion: 1 mol of KCl produces more osmotic pressure than 1 mol of urea.
Reason: KCl dissociates into two ions.
Answer: A

Q197.
Assertion: A solution with higher concentration has higher boiling point.
Reason: More solute = more elevation in boiling point.
Answer: A

Q198.
Assertion: Solution with stronger intermolecular forces shows lower vapour pressure.
Reason: Molecules find it harder to escape from liquid phase.
Answer: A

Q199.
Assertion: The molarity of water is 55.5 M.
Reason: 1000 g water = 55.5 mol; Volume = 1 L
Answer: A

Q200.
Assertion: Presence of non-volatile solute increases boiling point.
Reason: It decreases vapour pressure, requiring more heat to boil.
Answer: A

Q1. Match the concentration units with their formulas:

Column I Column II
A. Molarity (M) 1. Moles of solute / Volume of solution (L)
B. Molality (m) 2. Moles of solute / Mass of solvent (kg)
C. Mole fraction (χ) 3. Moles of component / Total moles
D. Mass percent (%) 4. (Mass of solute / Mass of solution) × 100

Answer: A-1, B-2, C-3, D-4

Q2. Match colligative properties with their formulas:

Column I Column II
A. Elevation in boiling pt 1. ΔTb = i × Kb × m
B. Freezing point depression 2. ΔTf = i × Kf × m
 Column I Column II
C. Osmotic pressure 3. π = i × C × R × T
D. Relative lowering of VP 4. ΔP / P° = χsolute

Answer: A-1, B-2, C-3, D-4

Q3. Match the type of solution with its deviation from Raoult’s law:

Column I Column II
A. Ideal solution 1. Obeys Raoult’s law
B. Positive deviation 2. A–B < A–A, B–B interaction
C. Negative deviation 3. A–B > A–A, B–B interaction
D. Azeotrope 4. Constant boiling mixture

Answer: A-1, B-2, C-3, D-4

Q4. Match solutes with their van’t Hoff factor:

Column I (1 mol) Column II (Van’t Hoff factor i)

A. Glucose (C6H12O6) 1. 1
B. NaCl 2. 2
C. BaCl₂ 3. 3
D. AlCl₃ 4. 4

Answer: A-1, B-2, C-3, D-4

Q5. Match processes with the required condition:

Column I Column II
A. Boiling 1. Vapour pressure = atm pressure
B. Freezing 2. Solid-liquid equilibrium
C. Osmosis 3. Semipermeable membrane
D. Reverse osmosis 4. Pressure > π

Answer: A-1, B-2, C-3, D-4

Q6. Match concentration units with their dependence:

Column I Column II
A. Molarity 1. Volume-based (temp. dependent)
B. Molality 2. Mass-based (temp. independent)
C. Mole fraction 3. Dimensionless
D. Normality 4. Gram equivalents / L

Answer: A-1, B-2, C-3, D-4

Q7. Match terms with their definitions:

Column I Column II
A. Solvent 1. Medium in which solute dissolves
B. Solute 2. Substance dissolved
C. Solution 3. Homogeneous mixture
D. Solubility 4. Max amount of solute in solvent

Answer: A-1, B-2, C-3, D-4

Q8. Match scenarios with their effect on colligative properties:

Column I Column II
A. Electrolyte solute 1. i > 1
B. Non-electrolyte solute 2. i = 1
C. Strong electrolyte 3. Complete dissociation
D. Weak electrolyte 4. Partial dissociation

Answer: A-1, B-2, C-3, D-4

Q9. Match quantities with their symbols:

Column I Column II
A. Osmotic pressure 1. π
B. Boiling point elevation 2. ΔTb
C. Freezing point depression 3. ΔTf
D. Van’t Hoff factor 4. i

Answer: A-1, B-2, C-3, D-4

Q10. Match the type of colligative property with the observed phenomenon:

Column I Column II
A. Lowering of VP 1. Escaping tendency reduced
B. Elevation in BP 2. Needs higher temp to boil
C. Freezing point depression 3. Freezing delayed
D. Osmosis 4. Solvent flows via membrane

Answer: A-1, B-2, C-3, D-4

Q11. Match the effect with the condition:

Column I Column II
A. Increase in temperature 1. Gas solubility decreases
B. Pressure increase 2. Gas solubility increases
C. Adding non-volatile solute 3. Vapour pressure lowers
 Column I Column II
D. Salt to ice 4. Freezing point decreases

Answer: A-1, B-2, C-3, D-4

Q12. Match the laws with their application:

Column I Column II
A. Raoult’s Law 1. VP of solution is proportional to mole fraction
B. Henry’s Law 2. Gas solubility ∝ partial pressure
C. Van’t Hoff Eqn 3. Osmotic pressure formula
D. Dalton’s Law 4. Total pressure = sum of partial pressures

Answer: A-1, B-2, C-3, D-4

Q13. Match solutes with their nature:

Column I (Solute) Column II (Type)

A. Glucose 1. Non-electrolyte
B. Na₂SO₄ 2. Strong electrolyte
C. CH₃COOH 3. Weak electrolyte
D. Ethanol 4. Volatile solute

Answer: A-1, B-2, C-3, D-4

Q14. Match concentration terms with key features:

Column I Column II
A. Molarity 1. Changes with temperature
B. Molality 2. Independent of temperature
C. Mole fraction 3. Unitless
D. Mass percent 4. Expressed as %

Answer: A-1, B-2, C-3, D-4

Q15. Match each colligative property with its use:

Column I Column II
A. Freezing pt depression 1. De-icing roads
B. Boiling pt elevation 2. Antifreeze in radiators
C. Osmotic pressure 3. Determination of molar mass
D. VP lowering 4. Determines volatility

Answer: A-1, B-2, C-3, D-4

Q16. Match type of deviation with real solutions:

 Column I Column II
A. Positive deviation 1. Ethanol + Acetone
B. Negative deviation 2. Acetone + Chloroform
C. Ideal solution 3. Benzene + Toluene
D. Strong deviation 4. HCl + H₂O

Answer: A-1, B-2, C-3, D-4

Q17. Match the symbol with the quantity:

Column I Column II
A. π 1. Osmotic pressure
B. ΔTb 2. Boiling point elevation
C. ΔTf 3. Freezing point depression
D. i 4. Van’t Hoff factor

Answer: A-1, B-2, C-3, D-4

Q18. Match the component with its role in a solution:

Column I Column II
A. Water 1. Solvent
B. Salt (NaCl) 2. Solute
C. Solution 3. Homogeneous mix
D. Saturated 4. Max solubility reached

Answer: A-1, B-2, C-3, D-4

Q19. Match application with colligative property:

Column I Column II
A. Pressure cooker 1. Elevated boiling point
B. Antifreeze 2. Lowered freezing point
C. Saline drip 3. Isotonic solution
D. Desalination 4. Reverse osmosis

Answer: A-1, B-2, C-3, D-4

Q20. Match formula with unit:

Column I Column II
A. π = iCRT 1. atm
B. ΔTb = iKbm 2. Kelvin (K)
C. Molarity (mol/L) 3. mol/L
D. Molality (mol/kg) 4. mol/kg
Answer: A-1, B-2, C-3, D-4

Q21. Match solutes with i value:

Column I (1 mol) Column II (i)

A. NaCl 1. 2
B. MgCl₂ 2. 3
C. K₂SO₄ 3. 3
D. Glucose 4. 1

Answer: A-1, B-2, C-3, D-4

Q22. Match colligative property with key dependency:

Column I Column II
A. Osmotic pressure 1. Concentration
B. Boiling pt elevation 2. Number of solute particles
C. Freezing pt depression 3. i × Kf × m
D. Vapour pressure lowering 4. Raoult’s law

Answer: A-1, B-2, C-3, D-4

Q23. Match applications with the principle:

Column I Column II
A. Pickling vegetables 1. Osmosis
B. IV drips 2. Isotonic solution
C. Desalination 3. Reverse osmosis
D. Road salt 4. Freezing point depression

Answer: A-1, B-2, C-3, D-4

Q24. Match effect with reason:

Column I Column II
A. VP lowering 1. Non-volatile solute added
B. BP elevation 2. More heat needed
C. FP depression 3. Solution stays liquid longer
D. Osmosis 4. Solvent flows through membrane

Answer: A-1, B-2, C-3, D-4

Q25. Match expressions with meaning:

Column I Column II
A. ΔTf = iKfm 1. Freezing pt depression
 Column I Column II
B. ΔTb = iKbm 2. Boiling pt elevation
C. π = iCRT 3. Osmotic pressure
D. ΔP / P₀ = χsolute 4. Vapour pressure lowering

Answer: A-1, B-2, C-3, D-4

Q26. Match terms with properties:

Column I Column II
A. Isotonic 1. Same osmotic pressure
B. Hypertonic 2. Higher solute conc.
C. Hypotonic 3. Lower solute conc.
D. Azeotrope 4. Constant boiling

Answer: A-1, B-2, C-3, D-4

Q27. Match solution with type:

Column I Column II
A. Sugar in water 1. Non-electrolyte
B. NaCl in water 2. Electrolyte
C. Ethanol in water 3. Liquid-liquid
D. Air 4. Gas-gas solution

Answer: A-1, B-2, C-3, D-4

Q28. Match concepts with law:

Column I Column II
A. Gas solubility 1. Henry’s law
B. VP of components 2. Raoult’s law
C. Total pressure (gas) 3. Dalton’s law
D. Osmotic pressure 4. Van’t Hoff equation

Answer: A-1, B-2, C-3, D-4

Q29. Match factor with its impact on colligative properties:

Column I Column II
A. Temp ↑ 1. Osmotic pressure ↑
B. Pressure ↑ 2. Gas solubility ↑
C. i ↑ 3. Greater colligative effect
D. m ↑ 4. Stronger effect

Answer: A-1, B-2, C-3, D-4

Q30. Match compound with dissociation:

Column I Column II (i value)

A. CaCl₂ 1. 3
B. KCl 2. 2
C. Al₂(SO₄)₃ 3. 5
D. C₆H₁₂O₆ (glucose) 4. 1

Answer: A-1, B-2, C-3, D-4

Q31. Match the concentration unit with its expression:

Column I Column II
A. Mole fraction 1. moles of A / total moles
B. Molality 2. moles of solute / kg of solvent
C. Molarity 3. moles of solute / L of solution
D. Parts per million 4. (mass of solute / total mass) × 10⁶

Answer: A-1, B-2, C-3, D-4

Q32. Match the following formulas with their constants:

Column I Column II
A. ΔTb = iKbm 1. Kb = molal elevation constant
B. ΔTf = iKfm 2. Kf = molal depression constant
C. π = iCRT 3. R = universal gas constant
D. i (Van’t Hoff) 4. accounts for particle dissociation

Answer: A-1, B-2, C-3, D-4

Q33. Match the system with the type of solution:

Column I Column II
A. O₂ dissolved in water 1. Gas in liquid
B. Ethanol in water 2. Liquid in liquid
C. Sugar in tea 3. Solid in liquid
D. Air (O₂ + N₂) 4. Gas in gas

Answer: A-1, B-2, C-3, D-4

Q34. Match the effect of solute on water:

Column I Column II
A. NaCl in water 1. i = 2, increases colligative effect
B. Glucose in water 2. i = 1, no dissociation
C. BaCl₂ in water 3. i = 3
 Column I Column II
D. CH₃COOH in water 4. i between 1 and 2 (partial)

Answer: A-1, B-2, C-3, D-4

Q35. Match deviations from Raoult’s law with the cause:

Column I Column II
A. Positive deviation 1. Weaker A–B interactions
B. Negative deviation 2. Stronger A–B interactions
C. Ideal solution 3. A–B ≈ A–A and B–B
D. Azeotrope 4. Constant boiling mixture

Answer: A-1, B-2, C-3, D-4

Q36. Match the type of pressure with its unit:

Column I Column II
A. Vapour pressure 1. mmHg or atm
B. Osmotic pressure 2. atm
C. Partial pressure 3. atm
D. Freezing point 4. Kelvin (K)

Answer: A-1, B-2, C-3, D-4

Q37. Match laws with statements:

Column I Column II
A. Raoult’s law 1. VP ∝ mole fraction
B. Henry’s law 2. C ∝ p (gas solubility)
C. Van’t Hoff 3. π = iCRT
D. Dalton’s law 4. Total P = p₁ + p₂ + …

Answer: A-1, B-2, C-3, D-4

Q38. Match real-world examples with solution types:

Column I Column II
A. Soda water 1. Gas in liquid
B. Vinegar 2. Liquid in liquid
C. Seawater 3. Solid in liquid
D. Air 4. Gas in gas
Answer: A-1, B-2, C-3, D-4

Q39. Match terms with their definitions:

Column I Column II
A. Osmotic pressure 1. Pressure to stop osmosis
B. Semipermeable membrane 2. Allows solvent but not solute
C. Reverse osmosis 3. Pressure > π to reverse solvent flow
D. Colligative property 4. Depends on number of solute particles

Answer: A-1, B-2, C-3, D-4

Q40. Match uses with concepts:

Column I Column II
A. IV fluids (saline) 1. Isotonic solutions
B. Desalination of seawater 2. Reverse osmosis
C. Antifreeze in car engines 3. Freezing point depression
D. Food preservation (salt/sugar) 4. Osmotic pressure