Which of the following statements is wrong -

Options

A. All methyl ketones give a positive iodoform test.
B. Acetaldehyde is the only aldehyde that gives iodoform test.
C. All secondary alcohols give positive iodoform test.
D. Any alcohol that can be oxidised to an acetyl group gives a positive iodoform test.

Answer

To solve the question regarding which of the following statements is wrong about the Adoform test, we will analyze each statement step by step.

### Step 1: Understanding the Adoform Test
The Adoform test is a chemical reaction that helps identify the presence of methyl ketones or certain aldehydes. The general reaction can be represented as:
\[ Y \text{C} = \text{O} \text{CH}_3 + \text{I}_2 + \text{NaOH} \rightarrow \text{Carboxylic Acid Salt} + \text{CHI}_3 \]
where CHI3 (iodoform) is the yellow precipitate that indicates a positive result.

### Step 2: Analyzing Each Statement
1. **Statement A**: "All methyl ketones give a positive Adoform test."
- This statement is **correct**. Methyl ketones (having the structure RCOCH3) will always yield a positive Adoform test.

2. **Statement B**: "Acetyldehyde is the only aldehyde that gives Adoform test."
- This statement is **correct**. Acetaldehyde (CH3CHO) is the only aldehyde that can give a positive Adoform test due to the presence of the methyl group.

3. **Statement C**: "All secondary alcohols give a positive Adoform test."
- This statement is **incorrect**. Not all secondary alcohols will yield a positive Adoform test. For example, a secondary alcohol that does not lead to the formation of a methyl ketone upon oxidation will not give a positive result.

4. **Statement D**: "Any alcohol that can be oxidized to an acetyl group gives a positive Adoform test."
- This statement is **correct**. If an alcohol can be oxidized to form an acetyl group (C=O with a methyl group), it will give a positive Adoform test.

### Conclusion
After analyzing all statements, we find that **Statement C** is the incorrect one.

### Final Answer
The wrong statement is: **"All secondary alcohols give a positive Adoform test."**

---