Class Test 

 8 questions based on Chapter: Solutions (Class 12 Chemistry, NCERT-based), including 2 specially focused on degree of association/dissociation:

Conceptual & Numerical Questions:

1. Define ideal and non-ideal solutions. Give one example of each.

2. State Raoult’s law for a solution containing volatile components. How is it related to the lowering of vapour pressure?

3. Differentiate between molarity and molality. Why is molality preferred over molarity in temperature-dependent calculations?

4. A solution is prepared by dissolving 10 g of a solute in 100 g of water. The boiling point elevation is found to be 0.52°C. Calculate the molar mass of the solute. (Given: Kb = 0.52 K kg mol⁻¹)

5. What is van't Hoff factor? How does it help in determining the degree of association or dissociation of a solute? (Conceptual, leads to degree questions)

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Special Questions on Degree of Association/Dissociation:

6. A solution of ethanoic acid in benzene shows a depression in freezing point corresponding to a van't Hoff factor (i) of 0.5. Calculate the degree of association of ethanoic acid molecules.

7. Potassium sulphate (K₂SO₄) dissociates in aqueous solution as:

K₂SO₄ → 2K⁺ + SO₄²⁻.

A 0.1 molal solution of K₂SO₄ has a freezing point depression of 0.558°C. Calculate the van’t Hoff factor and hence the degree of dissociation.

(Given Kf = 1.86 K kg mol⁻¹)

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Application-Based/Reasoning Questions:

8. Why does sodium chloride dissolved in water elevate the boiling point, while urea does not change the colligative properties to the same extent at the same molal concentration?

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8 questions based on Chapter: Solutions (Class 12 Chemistry, NCERT-based), including 2 aa specially focused on degree of association/dissociation:

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Conceptual & Numerical Questions:

1. Define ideal and non-ideal solutions. Give one example of each.

2. State Raoult’s law for a solution containing volatile components. How is it related to the lowering of vapour pressure?

3. Differentiate between molarity and molality. Why is molality preferred over molarity in temperature-dependent calculations?

4. A solution is prepared by dissolving 10 g of a solute in 100 g of water. The boiling point elevation is found to be 0.52°C. Calculate the molar mass of the solute. (Given: Kb = 0.52 K kg mol⁻¹)

5. What is van't Hoff factor? How does it help in determining the degree of association or dissociation of a solute? (Conceptual, leads to degree questions)

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Special Questions on Degree of Association/Dissociation:

6. A solution of ethanoic acid in benzene shows a depression in freezing point corresponding to a van't Hoff factor (i) of 0.5. Calculate the degree of association of ethanoic acid molecules.

7. Potassium sulphate (K₂SO₄) dissociates in aqueous solution as:
   K₂SO₄ → 2K⁺ + SO₄²⁻.
   A 0.1 molal solution of K₂SO₄ has a freezing point depression of 0.558°C. Calculate the van’t Hoff factor and hence the degree of dissociation.
   (Given Kf = 1.86 K kg mol⁻¹)

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Application-Based/Reasoning Questions:

8. Why does sodium chloride dissolved in water elevate the boiling point, while urea does not change the colligative properties to the same extent at the same molal concentration?

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