A : Temporary hardness is due to `HCO_(3)^(-)` ions.
R : permanent hardness is due to `CaCl_(2)`

Options

A. If both Assertion & Reason are true and the reason is the correct explanation of the assertion, then mark (1)
B. If both Assertion & Reason are true but the reason is not the correct explanantion of the assertion, then mark (2)
C. If assertion is true statements but Reason is false, then mark (3)
D. If both Assertion and Reason are false statements, then mark (4)

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Understanding Temporary Hardness
- **Assertion (A)**: Temporary hardness is due to `HCO3^(-)` ions.
- Temporary hardness in water is primarily caused by the presence of bicarbonate ions, specifically calcium bicarbonate (Ca(HCO3)2) and magnesium bicarbonate (Mg(HCO3)2). When water containing these bicarbonates is heated, the bicarbonates decompose, leading to the precipitation of calcium carbonate (CaCO3) and magnesium carbonate (MgCO3), which can be removed.

### Step 2: Understanding Permanent Hardness
- **Reason (R)**: Permanent hardness is due to `CaCl2`.
- Permanent hardness is caused by the presence of soluble salts of calcium and magnesium, which do not precipitate upon boiling. This includes chlorides (like CaCl2) and sulfates (like CaSO4) of calcium and magnesium. Therefore, the statement that permanent hardness is due to CaCl2 is correct.

### Step 3: Analyzing the Relationship
- Both the assertion and the reason are true statements. However, the reason does not explain the assertion. The assertion focuses on temporary hardness caused by bicarbonate ions, while the reason discusses permanent hardness caused by chlorides.

### Conclusion
- Since both the assertion and the reason are true, but the reason does not provide a correct explanation for the assertion, the answer is that both statements are true, but the reason is not a correct explanation of the assertion.

### Final Answer
- Both A and R are true, but R is not the correct explanation of A.

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