Which one will give positive iodoform test?

Options

A. `CH_(3) - CH_(2) `- OH
B. `CH_(3) - "COOCH"_(3)`
C. `CH_(3) - CH_(2) - CO - CH_(3) - CH_(3)`
D. `CH_(3) - underset(CH_(3))underset(|)(CH) - CO - CH_(2) - CH_(3)`

Answer

To determine which compound gives a positive iodoform test, we need to understand the conditions under which this test is positive. The iodoform test is used to identify methyl ketones and certain alcohols, particularly those that can be oxidized to methyl ketones.

### Step-by-Step Solution:

1. **Understanding the Iodoform Test**:
- The iodoform test is a qualitative test for the presence of methyl ketones or secondary alcohols that can be oxidized to methyl ketones. The reaction involves the formation of iodoform (CHI3) when the compound reacts with iodine (I2) in the presence of a base (usually NaOH).

2. **Identifying the Compounds**:
- List the compounds you are considering for the iodoform test. Common candidates include:
- Methyl ketones (e.g., acetone)
- Ethanol (a secondary alcohol)
- Aldehydes (specifically acetaldehyde)
- Esters (which typically do not give a positive test)

3. **Analyzing Each Compound**:
- **Methyl Ketones**: Compounds like acetone (CH3COCH3) will give a positive iodoform test because they contain the methyl group adjacent to the carbonyl group.
- **Ethanol**: Ethanol (CH3CH2OH) can be oxidized to acetaldehyde (CH3CHO), which will also give a positive iodoform test.
- **Aldehydes**: Acetaldehyde (CH3CHO) will give a positive test as it can be oxidized to a methyl ketone.
- **Esters**: Esters generally do not give a positive iodoform test as they do not have the necessary structure.

4. **Conclusion**:
- From the analysis, the compounds that will give a positive iodoform test are methyl ketones (like acetone), ethanol, and acetaldehyde. If the question provides specific options, the correct answer would be the one that is either a methyl ketone or can be oxidized to one.

### Final Answer:
The compound that gives a positive iodoform test is **acetaldehyde** or **ethanol** (if it is among the options).