Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : An aqueous solution of `KOH `when used for volumetric analysis, its concentration should be checked before the use.
Reason (R) : On aging, `KOH` solution absorbs atmospheric `CO_2.`
In the light of the above statements, choose the correct answer from the options given below :

Options

A. (A) is correct but (R) is not correct
B. (A) is not correct but (R) is correct
C. Both (A) and (R) are correct but (R) is not the correct explanation of (A)
D. Both (A) and (R) are correct and (R) is the correct explanation of (A)

Answer

To solve the question, we need to analyze both the Assertion (A) and the Reason (R) provided.

### Step 1: Analyze the Assertion (A)
The assertion states: "An aqueous solution of KOH when used for volumetric analysis, its concentration should be checked before the use."

**Explanation**: This statement is correct because the concentration of KOH is crucial for accurate volumetric analysis. If the concentration is not known or has changed, the results of the analysis may be inaccurate.

### Step 2: Analyze the Reason (R)
The reason states: "On aging, KOH solution absorbs atmospheric CO2."

**Explanation**: This statement is also correct. KOH is a strong base that can react with carbon dioxide (CO2) from the atmosphere, leading to the formation of potassium carbonate (K2CO3). This reaction alters the concentration of KOH in the solution over time.

### Step 3: Determine the relationship between Assertion and Reason
Since both the assertion and the reason are true, we need to check if the reason correctly explains the assertion.

**Explanation**: The reason explains why the concentration of KOH should be checked before use: because it can absorb CO2 from the atmosphere, which would affect its concentration. Therefore, the reason supports the assertion.

### Conclusion
Both the assertion and the reason are true, and the reason correctly explains the assertion.

### Final Answer
The correct answer is that both the Assertion (A) and Reason (R) are true, and the reason explains the assertion.

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