`CH_3-C-=C-CH_3 underset((ii)H_2O //Zn)overset((i)X)to CH_3-undersetunderset(O)(||)C-undersetunderset(O)(||)C-CH_3` X is

Options

A. `HNO_3`
B. `O_2`
C. `O_3`
D. `KMnO_4`

Answer

To solve the given question, we need to identify the reagent \( X \) that converts the alkyne \( CH_3-C \equiv C-CH_3 \) into the corresponding diketone \( CH_3-C(=O)-C(=O)-CH_3 \).

### Step-by-Step Solution:

1. **Identify the Starting Material**:
The starting material is 2-butyne, which has the structure \( CH_3-C \equiv C-CH_3 \). This compound contains a triple bond between two carbon atoms.

2. **Understanding the Reaction**:
The reaction involves the conversion of the triple bond into two carbonyl groups (C=O). This transformation is characteristic of ozonolysis, where the triple bond is cleaved and carbonyl groups are formed.

3. **Determine the Reagent \( X \)**:
In ozonolysis, ozone (O3) is used to cleave double or triple bonds. The reaction typically proceeds through the formation of an ozonide intermediate, which is then reduced to yield carbonyl compounds.

4. **Reduction Step**:
The presence of \( H_2O \) and \( Zn \) indicates that the ozonide is being reduced. This step is crucial because it converts the ozonide into the final diketone product.

5. **Final Product**:
The final product is \( CH_3-C(=O)-C(=O)-CH_3 \), which is 2,3-butanedione (or diacetyl). This confirms that the reaction indeed involves the ozonolysis of the alkyne.

6. **Conclusion**:
Therefore, the reagent \( X \) that facilitates this transformation is ozone (O3).

### Final Answer:
\( X = O_3 \)