Which of the following does not give iodoform:

Options

A. Acetic acid
B. Lactic acid
C. Acetophenone
D. Propionic acid

Answer

To determine which of the following compounds does not give the iodoform test, we need to understand the conditions under which the iodoform test is positive. The iodoform test is typically positive for compounds that have a methyl ketone group (CH3CO-) or a secondary alcohol that can be oxidized to a methyl ketone.

### Step-by-Step Solution

1. **Identify the Compounds**: The question presents several compounds. We need to analyze each one to see if it can give a positive iodoform test. The compounds mentioned are:
- Acetic acid (CH3COOH)
- Lactic acid (CH3CHOHCOOH)
- Acetophenone (C6H5COCH3)
- Propanoic acid (CH3CH2COOH)

2. **Analyze Acetic Acid (CH3COOH)**:
- Acetic acid is a carboxylic acid and does not contain a methyl ketone group or a secondary alcohol that can be oxidized to a methyl ketone. Therefore, it does not give a positive iodoform test.

3. **Analyze Lactic Acid (CH3CHOHCOOH)**:
- Lactic acid contains a hydroxyl group (–OH) adjacent to a carbonyl group (–COOH). This structure allows it to be oxidized to form a methyl ketone, thus it gives a positive iodoform test.

4. **Analyze Acetophenone (C6H5COCH3)**:
- Acetophenone is a methyl ketone (CH3CO-) and will give a positive iodoform test when reacted with iodine and a base.

5. **Analyze Propanoic Acid (CH3CH2COOH)**:
- Propanoic acid is also a carboxylic acid and does not have a methyl ketone group or a secondary alcohol that can be oxidized to a methyl ketone. Therefore, it does not give a positive iodoform test.

6. **Conclusion**:
- The compounds that do not give the iodoform test are acetic acid and propanoic acid. Therefore, the answer to the question is that both options 1 (Acetic acid) and 4 (Propanoic acid) do not give the iodoform test.

### Final Answer:
The compounds that do not give the iodoform test are:
- **Acetic acid (Option 1)**
- **Propanoic acid (Option 4)**