Assertion : Phenol is more acidic then m-methoxy phenol
Reason : `-OCH_(3)` shows `+I` effect

Answer

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

### Step-by-Step Solution:

1. **Understanding the Assertion**:
- The assertion states that "Phenol is more acidic than m-methoxy phenol."
- To evaluate this, we need to compare the acidity of phenol and m-methoxy phenol.

2. **Structures of the Compounds**:
- **Phenol**: The structure of phenol is C6H5OH. It has a hydroxyl (-OH) group attached to a benzene ring.
- **m-Methoxy Phenol**: The structure of m-methoxy phenol is C6H4(OH)(OCH3), where the methoxy (-OCH3) group is attached to the meta position relative to the hydroxyl group.

3. **Acidity Comparison**:
- The acidity of phenolic compounds is influenced by the stability of the phenoxide ion formed after deprotonation.
- In phenol, the negative charge on the oxygen in the phenoxide ion is stabilized by resonance with the benzene ring.
- In m-methoxy phenol, the methoxy group is an electron-donating group due to its +I (inductive) effect, which destabilizes the negative charge on the oxygen of the phenoxide ion.

4. **Resonance Structures**:
- For phenol, the phenoxide ion can delocalize the negative charge through resonance, leading to several resonance structures that stabilize the ion.
- For m-methoxy phenol, the resonance structures are also possible, but the presence of the methoxy group does not stabilize the negative charge as effectively as in phenol.

5. **Conclusion on Assertion**:
- Since the methoxy group destabilizes the phenoxide ion due to its electron-donating effect, phenol is indeed more acidic than m-methoxy phenol.
- Therefore, the assertion is **correct**.

6. **Understanding the Reason**:
- The reason states that "-OCH3 shows +I effect."
- The methoxy group (-OCH3) does exhibit a +I effect (inductive effect), which means it donates electron density through the sigma bond.

7. **Conclusion on Reason**:
- The statement about the methoxy group showing a +I effect is **correct**.
- However, the assertion is correct, but the reason does not explain the assertion correctly since it suggests that the +I effect would increase acidity, which is not the case here.

### Final Conclusion:
- **Assertion**: Correct (Phenol is more acidic than m-methoxy phenol).
- **Reason**: Correct but does not explain the assertion properly.

### Final Answer:
Both the assertion and reason are correct, but the reason does not correctly explain the assertion.

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