How many of the given compounds can produce `XeO_3`.
`XeF_6,XeF_4, XeO_2F_2, XeOF_4 `

Answer

To determine how many of the given compounds can produce `XeO3`, we will analyze each compound individually and see if hydrolysis or reaction with another compound can yield `XeO3`.

### Step-by-Step Solution:

1. **Analyze `XeF6`:**
- When `XeF6` is hydrolyzed, it reacts with water to produce `XeO3` and `HF`.
- Reaction:
\[ XeF_6 + 3H_2O \rightarrow XeO_3 + 6HF \]
- **Conclusion:** `XeF6` can produce `XeO3`.

2. **Analyze `XeF4`:**
- When `XeF4` is hydrolyzed, it also produces `XeO3`, along with `HF` and oxygen.
- Reaction:
\[ XeF_4 + 2H_2O \rightarrow XeO_3 + 4HF + O_2 \]
- **Conclusion:** `XeF4` can produce `XeO3`.

3. **Analyze `XeO2F2`:**
- `XeO2F2` can react with `SiO2` to produce `XeO3` and `SiF4`.
- Reaction:
\[ XeO_2F_2 + SiO_2 \rightarrow XeO_3 + SiF_4 \]
- **Conclusion:** `XeO2F2` can produce `XeO3`.

4. **Analyze `XeOF4`:**
- When `XeOF4` reacts with `SiO2`, it produces `XeO2F2` and `SiF4`, but does not directly produce `XeO3`.
- Reaction:
\[ XeOF_4 + SiO_2 \rightarrow XeO_2F_2 + SiF_4 \]
- **Conclusion:** `XeOF4` does not produce `XeO3`.

### Final Count:
- The compounds that can produce `XeO3` are `XeF6`, `XeF4`, and `XeO2F2`.
- Therefore, the total number of compounds that can produce `XeO3` is **3**.

### Summary:
The answer is that **3 compounds** (`XeF6`, `XeF4`, and `XeO2F2`) can produce `XeO3`.