Choose the INCORRECT statement :

Options

A. Salicylic acid (o-hydroxybenzoic acid ) is stronger acid than its m-, p-isomers and benzoic acid itself
B. Acidity of salicylic acid is increases due to steric inhibition of resonance , as - OH group forces COOH out of the plane
C. The orbitals which are in the same plane take part in resonance
D. All the resonating structures have real existence

Explanation

To solve the question of identifying the INCORRECT statement among the given options, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Understanding the First Statement:**
- The first statement claims that salicylic acid (ortho-hydroxybenzoic acid) is a stronger acid than its meta and para isomers as well as benzoic acid itself.
- **Analysis:** This is true because of the ortho effect, where the presence of the hydroxyl group at the ortho position increases acidity due to hydrogen bonding and stabilization of the conjugate base.

2. **Understanding the Second Statement:**
- The second statement states that the acidity of salicylic acid is increased due to the steric inhibition of resonance effect.
- **Analysis:** This is also true. The steric effects and resonance stabilization contribute to the increased acidity of salicylic acid.

3. **Understanding the Third Statement:**
- The third statement mentions that orbitals which are in the same plane take part in resonance.
- **Analysis:** This statement is correct. For resonance to occur, the involved orbitals must be in the same plane to allow for maximum overlap.

4. **Understanding the Fourth Statement:**
- The fourth statement asserts that all resonating structures have real existence.
- **Analysis:** This statement is INCORRECT. In reality, not all resonating structures are real; only the resonance hybrid, which is a combination of the most stable structures, has real existence. The other structures are merely theoretical constructs.

### Conclusion:
Based on the analysis of each statement, the INCORRECT statement is the fourth one, which claims that all resonating structures have real existence.

### Final Answer:
**The INCORRECT statement is:** "All the resonating structures have real existence."

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