Which of the following statemenet (s) is/are correct ?

Options

A. `3,5-`Dimethy1-4-nitrophenol (I) is less acidic than the isomeric `2,6-`demthy-4-nitrophenol (II) .
B. `(I)` is more acidic than `(II)`
C. `I` is less acidic than `(II)` due to steric inhibition of resonance of two `(Me)` groups with `(NO_2)` group.
D. `(I)` is more acidic than `(II)` due to less `+ I` effect of two `(Me)` groups in `(I)`

Answer

To determine which statements about the acidity of the compounds are correct, we will analyze the structure and substituents of the two compounds mentioned: Dimethyl-1,4-nitrophenol and Isomeric-2,6-dimethyl-4-nitrophenol.

### Step-by-Step Solution:

1. **Identify the Structures**:
- The first compound is **Dimethyl-1,4-nitrophenol**. Here, the nitro group (NO2) is at the para position relative to the hydroxyl group (OH), and there are two methyl groups (CH3) at the 1 and 4 positions.
- The second compound is **Isomeric-2,6-dimethyl-4-nitrophenol**. In this compound, the nitro group is at the para position relative to the hydroxyl group, but the methyl groups are at the ortho positions (2 and 6).

2. **Analyze Acidity**:
- The presence of the nitro group, which is an electron-withdrawing group, increases the acidity of the hydroxyl group by stabilizing the negative charge on the phenoxide ion formed upon deprotonation.
- In the first compound, the nitro group can effectively stabilize the negative charge due to resonance.
- In the second compound, the two methyl groups at the ortho position create steric hindrance, which inhibits the resonance interaction between the nitro group and the hydroxyl group. This results in a less stable phenoxide ion.

3. **Compare Acidity**:
- Due to the steric hindrance in the second compound, the first compound (Dimethyl-1,4-nitrophenol) is less acidic than the second compound (Isomeric-2,6-dimethyl-4-nitrophenol).
- Therefore, we conclude that:
- **Option A**: Correct (1st compound is less acidic than 2nd)
- **Option B**: Incorrect (1st compound is not more acidic than 2nd)
- **Option C**: Correct (1st is less acidic due to steric inhibition of resonance)
- **Option D**: Incorrect (1st is not more acidic due to the +I effect of methyl groups)

4. **Final Conclusion**:
- The correct options are A and C.

### Summary of Correct Statements:
- **Correct Statements**: A and C
- **Incorrect Statements**: B and D