Assertion (A): Carbon dioxide turns lime water milky.
Reason (R ): Carbon dioxide sullies the water.

Options

A. Both A and R are true and R is the correct explanation of A.
B. Both A and R are true but R is NOT the correct explanation of A.
C. A is true but R is false.
D. A is false and R is true.

Explanation

To analyze the given assertion and reason, we will break down the statements and evaluate their validity step by step.

### Step 1: Understanding the Assertion
- **Assertion (A)**: "Carbon dioxide turns lime water milky."
- Lime water is a dilute solution of calcium hydroxide (Ca(OH)₂). When carbon dioxide (CO₂) is bubbled through lime water, it reacts with calcium hydroxide to form calcium carbonate (CaCO₃), which is insoluble in water and appears as a white precipitate, making the solution look milky.

**Conclusion**: The assertion is **true**.

### Step 2: Understanding the Reason
- **Reason (R)**: "Carbon dioxide sullies the water."
- The term "sully" means to damage the purity of something. In this context, the statement implies that carbon dioxide contaminates or makes the water impure. However, carbon dioxide does not sully water in the sense of making it impure; rather, it reacts with lime water to produce a precipitate.

**Conclusion**: The reason is **false**.

### Step 3: Evaluating the Relationship
- Since the assertion is true and the reason is false, we can conclude that the reason does not support the assertion.

### Final Conclusion
- The assertion (A) is true, while the reason (R) is false. Therefore, the correct response to the question is that the assertion is true, but the reason is not a valid explanation for the assertion.

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