A : Phenol does not react with `NaHCO_(3)` .
R : Phenol is less acidic than `H_(2)CO_(3)`

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 explanation of the assertion, then mark (2)
C. If Assertion is true statement but Reason is false , then mark (3)
D. If both Assertion and Reason are false statements , then mark (4)

Answer

To analyze the assertion and reason provided in the question, we will break down the information step by step.

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Phenol does not react with NaHCO3."
- To evaluate this, we need to understand the nature of phenol and NaHCO3. NaHCO3 (sodium bicarbonate) is a weak base and can react with acids to form carbon dioxide, water, and a salt.

2. **Understanding the Reaction**:
- For a reaction to occur between phenol and NaHCO3, phenol must be acidic enough to donate a proton (H⁺) to NaHCO3.
- If phenol is less acidic than the acid that NaHCO3 can produce (which is carbonic acid, H2CO3), then phenol will not react.

3. **Analyzing the Reason**:
- The reason states that "Phenol is less acidic than H2CO3."
- This is indeed true. H2CO3 is a stronger acid compared to phenol. Therefore, phenol cannot donate a proton to NaHCO3 because H2CO3 would prefer to remain in its acidic form rather than dissociate.

4. **Conclusion**:
- Since phenol does not react with NaHCO3 due to its lower acidity compared to H2CO3, both the assertion and reason are true.
- Furthermore, the reason correctly explains why the assertion is true.

5. **Final Answer**:
- Both the assertion (A) and the reason (R) are true, and the reason is the correct explanation of the assertion.