61. What is the molarity of a solution containing 98 g of H₂SO₄ in 500 mL of solution?
(Molecular weight of H₂SO₄ = 98 g/mol)
a) 1 M
b) 2 M
c) 3 M
d) 4 M
Answer: b) 2 M
62. Which of the following will show the highest freezing point depression?
a) 1 M glucose
b) 1 M NaCl
c) 1 M AlCl₃
d) 1 M K₂SO₄
Answer: c) 1 M AlCl₃
Explanation:
Freezing point depression depends on the number of particles in solution. AlCl₃ dissociates into 4 ions (Al³⁺ and 3 Cl⁻), giving the highest particle concentration compared to NaCl (2 ions), K₂SO₄ (3 ions), and glucose (which doesn’t dissociate).
63. A 0.2 M solution of NaOH has a density of 1.02 g/mL. What is the molality of the solution?
(Molecular weight of NaOH = 40 g/mol)
a) 0.21 mol/kg
b) 0.23 mol/kg
c) 0.25 mol/kg
d) 0.27 mol/kg
Answer: b) 0.23 mol/kg
64. If 1.5 moles of solute are dissolved in 3 kg of solvent, what is the molality of the solution?
a) 0.25 mol/kg
b) 0.5 mol/kg
c) 0.75 mol/kg
d) 1 mol/kg
Answer: b) 0.5 mol/kg
65. How many grams of NaOH are needed to prepare 250 mL of a 2 M solution?
(Molecular weight of NaOH = 40 g/mol)
a) 10 g
b) 15 g
c) 20 g
d) 25 g
Answer: d) 20 g
Explanation:
Moles of NaOH = Molarity × Volume = 2 mol/L×0.25 L=0.5 mol
Mass of NaOH = 0.5 mol×40 g/mol=20 g
66. A solution contains 3 moles of solute in 4 kg of solvent. What is the molality of the solution?
a) 0.5 mol/kg
b) 0.75 mol/kg
c) 1.0 mol/kg
d) 1.25 mol/kg
Answer: d) 0.75 mol/kg
67. Which of the following solutions has the lowest freezing point?
a) 1 M NaCl
b) 1 M glucose
c) 1 M AlCl₃
d) 1 M K₂SO₄
Answer: c) 1 M AlCl₃
Explanation:
The depression in freezing point depends on the number of particles. AlCl₃ dissociates into 4 ions, which leads to the highest freezing point depression among the given options.
68. How many moles of solute are present in 2 L of a 0.5 M solution?
a) 0.25 mol
b) 0.5 mol
c) 1 mol
d) 2 mol
Answer: c) 1 mol
Explanation:
Moles of solute = Molarity × Volume
Moles of solute = 0.5 M×2 L=1 mol
69. What is the mole fraction of solute in a solution containing 0.2 moles of solute and 0.8 moles of solvent?
a) 0.1
b) 0.2
c) 0.5
d) 0.8
Answer: b) 0.2
70. Which of the following is used to express the concentration of a solution for non-ideal solutions where volume is not additive?
a) Molarity
b) Molality
c) Mole fraction
d) Normality
Answer: c) Mole fraction
Explanation:
Mole fraction is ideal for non-ideal solutions where volume is not additive because it’s based on the number of moles and is independent of volume.
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