Which one gives the iodoform test?

Options

A. `CH_(3)`COOH
B. `CH_(3)CHO`
C. `CH_(3)"COOCH"_(3)`
D. `CH_(3)`COCl

Answer

To determine which compound gives the iodoform test, we need to understand the requirements for a positive iodoform test. The iodoform test is used to identify the presence of a methyl carbonyl group (specifically, a methyl ketone or an aldehyde with a methyl group adjacent to the carbonyl).

### Step-by-Step Solution:

1. **Identify the Structure of Compounds**:
We need to analyze the structures of the given compounds to check for the presence of a methyl carbonyl group (C=O) adjacent to a methyl group (CH3).

2. **Check for Methyl Ketone or Aldehyde**:
- A compound must have the structure R-CO-CH3 (methyl ketone) or R-CHO (aldehyde) where R can be hydrogen, alkyl, or aryl.
- The presence of a methyl group (CH3) next to the carbonyl is crucial for a positive test.

3. **Analyze Each Given Option**:
- **Option 1**: CH3-COOH (Acetic acid) - This does not have the required structure (no methyl ketone).
- **Option 2**: CH3-CO-CH3 (Acetone) - This is a methyl ketone and will give a positive iodoform test.
- **Option 3**: CH3-CO-O-CH3 (Methyl acetate) - This has an ester structure and does not meet the requirements.
- **Option 4**: CH3-CO-Cl (Acetyl chloride) - This has a halogen instead of an alkyl group and will not give a positive test.

4. **Conclusion**:
The only compound that meets the criteria for the iodoform test is **Option 2: CH3-CO-CH3 (Acetone)**, which is a methyl ketone.

### Final Answer:
**Option 2: CH3-CO-CH3 (Acetone)** gives a positive iodoform test.

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