Assertion: The pH of a buffer solution does not change appreciably on additions of a small amount of an acid or a base.
Reason: A buffer solution consists of either a weak acid and its salt with a strong base or a weak base its salt with a strong acid.

Options

A. If both Assertion and Reason are CORRECT and a Reason is the CORRECT explanations of the Assertion
B. If both Assertion and Reason are CORRECT but Reaon is not CORRECT explanation of the Assertion.
C. If Assertion is CORRECT but Reasson is INCORRECT.
D. If Assertion is INCORRECT but Reason is CORRECT.

Answer

To analyze the given assertion and reason regarding buffer solutions, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that the pH of a buffer solution does not change appreciably upon the addition of a small amount of an acid or a base.
- This is a fundamental property of buffer solutions, which are designed to resist changes in pH.

2. **Understanding the Reason**:
- The reason provided explains that a buffer solution consists of either a weak acid and its salt with a strong base or a weak base and its salt with a strong acid.
- This composition is crucial because it allows the buffer to neutralize added acids or bases without significantly altering the pH.

3. **Mechanism of Buffer Action**:
- When a small amount of acid is added to a buffer solution, the weak base (or the conjugate base from the weak acid) reacts with the added H⁺ ions, forming a weak acid. This minimizes the change in pH.
- Conversely, when a small amount of base is added, the weak acid in the buffer donates H⁺ ions to neutralize the added OH⁻ ions, again minimizing the change in pH.

4. **Conclusion**:
- Since both the assertion and reason are correct and the reason accurately explains why the assertion holds true, we conclude that the correct option is that both the assertion and reason are correct, and the reason is the correct explanation of the assertion.

### Final Answer:
Both the assertion and reason are correct, and the reason is the correct explanation of the assertion.

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