Question

Statement-I: \( K_b \) is more than \( K_f \) for water.
Statement-II: When we add a non-volatile solute in water, elevation in boiling point is more than depression in freezing point.

• A. Both Statement I and Statement II are correct.
• B. Statement I is correct but Statement II is incorrect.
• C. Statement I is incorrect but Statement II is correct.
• D. Both Statement I and Statement II are incorrect.

Answer 1

The Correct Option is D

Step 1: Understanding Statement-I.
The relation between the elevation in boiling point and depression in freezing point is governed by the ebullioscopic constant \( K_b \) and cryoscopic constant \( K_f \). For water, the values of \( K_b \) and \( K_f \) are related, but it's a known fact that \( K_b \) for water is less than \( K_f \), not more. Hence, Statement-I is incorrect.

Step 2: Understanding Statement-II.
Statement-II states that when a non-volatile solute is added to water, the elevation in boiling point is more than the depression in freezing point. However, in practice, the depression in freezing point is always greater than the elevation in boiling point for most solutions due to the relative magnitudes of \( K_f \) and \( K_b \). Hence, Statement-II is also incorrect.

Step 3: Conclusion.
Both statements are incorrect, so the correct answer is (D). Final Answer: Both Statement I and Statement II are incorrect.