Iodoform test is not given by : -

Options

A. `C_(6)H_(5)COC_(6)H_(5)`
B. `CH_(3)COCH_(3)`
C. `CH_(3)CH_(2)COCH_(3)`
D. `CH_(3)CH_(2)CHOHCH_(3)`

Answer

To determine which compound does not give a positive iodoform test, we need to understand the conditions necessary for the iodoform test to occur. The iodoform test is performed using sodium hydroxide (NaOH) and excess iodine (I2), and it is specifically applicable to compounds that contain a methyl ketone structure (R-C(=O)-CH3) or certain alcohols that can be oxidized to form a methyl ketone.

### Step-by-step Solution:

1. **Identify the Reagents**: The iodoform test requires NaOH and excess I2.

2. **Understand the Structure Required**: For a compound to give a positive iodoform test, it must contain a methyl ketone structure or a secondary alcohol that can be oxidized to a methyl ketone. The general structure for a methyl ketone is R-C(=O)-CH3, where R can be any alkyl or aryl group.

3. **Analyze the Options**:
- **Option 1: C6H5-CO-C6H5 (Benzophenone)**: This compound has the structure C6H5-C(=O)-C6H5. There are no methyl groups adjacent to the carbonyl carbon, so it does not have the required methyl ketone structure. Therefore, it will **not** give a positive iodoform test.
- **Option 2: CH3COOCH3 (Methyl Acetate)**: This compound can be hydrolyzed to CH3COOH and CH3OH, which does not contain a methyl ketone structure. Thus, it will also **not** give a positive iodoform test.
- **Option 3: CH3CH2C(=O)CH3 (Butan-2-one)**: This compound has the structure of a methyl ketone (C(=O)-CH3). Therefore, it will give a positive iodoform test.
- **Option 4: CH3CH2CH(OH)CH3 (2-Butanol)**: This is a secondary alcohol. Upon oxidation, it can be converted to a methyl ketone (butan-2-one), which will also give a positive iodoform test.

4. **Conclusion**: The only compound that does not give a positive iodoform test is **Option 1: C6H5-CO-C6H5**.

### Final Answer:
The compound that does not give a positive iodoform test is **C6H5-CO-C6H5** (Benzophenone).