Positive iodofonn test is given by

Options

A. acetamide
B. acetophenone
C. methylene
D. 1-hydroxypropane.

Answer

To determine which compound gives a positive iodoform test, we need to understand the requirements for a compound to react positively in this test. The iodoform test is specifically positive for compounds that have a methyl ketone structure (RCOCH3) or a compound that can be oxidized to form such a structure.

### Step-by-Step Solution:

1. **Identify the Compounds**: The question provides four compounds: Acetamide, Acetophenone, Methylene, and One Hydroxy Propane.

2. **Analyze Acetamide (CH3CONH2)**:
- Acetamide has an amide functional group (NH2).
- For the iodoform test, we need a methyl group adjacent to a carbonyl (C=O) group.
- The presence of the NH2 group makes it unable to lose the alpha hydrogen from the methyl group (CH3) because the NH2 will react instead.
- **Conclusion**: Acetamide does not give a positive iodoform test.

3. **Analyze Acetophenone (CH3C6H5CO)**:
- Acetophenone is a ketone with the structure RCOCH3 (where R is a phenyl group).
- It has a methyl group adjacent to the carbonyl group, which is necessary for the iodoform test.
- When treated with iodine (I2) and sodium hydroxide (NaOH), it can undergo the reaction to form iodoform (CHI3).
- **Conclusion**: Acetophenone gives a positive iodoform test.

4. **Analyze Methylene (CH2)**:
- Methylene is a simple hydrocarbon (CH2) and does not contain a carbonyl group.
- It cannot undergo the iodoform reaction because it lacks the necessary structure (methyl ketone).
- **Conclusion**: Methylene does not give a positive iodoform test.

5. **Analyze One Hydroxy Propane (C3H8O)**:
- One Hydroxy Propane (also known as propan-1-ol) does not have the required methyl ketone structure.
- It lacks the carbonyl group necessary for the iodoform test.
- **Conclusion**: One Hydroxy Propane does not give a positive iodoform test.

### Final Conclusion:
The only compound that gives a positive iodoform test is **Acetophenone**.