An oxide X in the normal form is almost non-reactive due to very high X - O bond enthalpy. It resists the attack by halogens, hydrogen and most of acids and metals even at elevated temperature. It is only attacked by HF and NaOH. The oxide X is.

Options

A. `SiO_(2)`
B. `CO_(2)`
C. `SnO_(2)`
D. `PbO_(2)`

Explanation

To solve the question regarding the oxide X, we need to analyze the properties described and identify the correct oxide among the given options: SiO2, CO2, and SnO2.

### Step 1: Understand the properties of oxide X
The oxide X is described as:
- Almost non-reactive due to very high X-O bond enthalpy.
- Resists attack by halogens, hydrogen, most acids, and metals even at elevated temperatures.
- Only attacked by HF (hydrofluoric acid) and NaOH (sodium hydroxide).

### Step 2: Analyze the options
1. **SiO2 (Silicon Dioxide)**:
- Has a very high bond enthalpy due to its strong covalent bonds in a giant covalent structure.
- It is known to be non-reactive with most substances, including halogens and acids, and is insoluble in water.
- It can be attacked by HF and strong bases like NaOH.

2. **CO2 (Carbon Dioxide)**:
- CO2 is a gas at room temperature and can react with water to form carbonic acid (H2CO3).
- It is not non-reactive and can easily react with various substances.

3. **SnO2 (Tin Dioxide)**:
- SnO2 can react with acids and bases, and it is not as stable as SiO2.
- It does not exhibit the same level of resistance to reactions as SiO2.

### Step 3: Conclusion
Based on the analysis, the oxide X that fits all the criteria of being almost non-reactive, having a high X-O bond enthalpy, and being attacked only by HF and NaOH is **SiO2** (Silicon Dioxide).

### Final Answer:
The oxide X is **SiO2**.

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