In the preparation of compounds of Xe, Bartlett had taken `O_(2)^(+) Pt F_(6)^(-)` as a base compound. This is because

Options

A. both `O_(2) and Xe` have same size
B. both `O_(2) and Xe` have same electron gain enthalpy
C. both `O_(2) and Xe` have almost same ionisation enthalpy
D. both `Xe and O_(2)` are gases.

Explanation

To solve the question regarding why Bartlett used \( O_2^{+} PtF_6^{-} \) as a base compound in the preparation of xenon compounds, we need to analyze the given options and determine which one is correct based on the properties of xenon and oxygen.

### Step-by-step Solution:

1. **Understanding the Context**:
- Bartlett was a chemist known for his work on noble gases, particularly xenon. He synthesized xenon compounds by using a strong oxidizing agent, which in this case is \( O_2^{+} PtF_6^{-} \).

2. **Analyzing the Options**:
- **Option 1**: Both oxygen and xenon have the same size.
- **Option 2**: Both oxygen and xenon have the same electron gain enthalpy.
- **Option 3**: Both xenon and oxygen have almost the same ionization enthalpy.
- **Option 4**: Both xenon and oxygen are gases.

3. **Comparing Ionization Enthalpies**:
- The ionization enthalpy of oxygen is approximately 1180 kJ/mol.
- The ionization enthalpy of xenon is approximately 1176 kJ/mol.
- Since these values are very close to each other, we can conclude that the ionization enthalpies of xenon and oxygen are almost equal.

4. **Conclusion**:
- Based on the analysis, the correct reason for using \( O_2^{+} PtF_6^{-} \) as a base compound in the preparation of xenon compounds is that **both xenon and oxygen have almost the same ionization enthalpy**. Therefore, **Option 3** is the correct answer.

### Final Answer:
The reason Bartlett used \( O_2^{+} PtF_6^{-} \) as a base compound is that both xenon and oxygen have almost the same ionization enthalpy.

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