The oxide of nitrogen existing in the solid state at room temperature is

Options

A. `NO`
B. `NO_(2)`
C. `N_(2)O_(3)`
D. `N_(2)O_(5)`

Answer

To determine which oxide of nitrogen exists in the solid state at room temperature, we will analyze the options provided: NO2, N2O3, and N2O5.

### Step-by-step Solution:

1. **Identify the Oxides of Nitrogen**: The oxides of nitrogen we are considering are:
- Nitrogen dioxide (NO2)
- Dinitrogen trioxide (N2O3)
- Dinitrogen pentoxide (N2O5)

2. **Check Physical States at Room Temperature**:
- **NO2**: This compound is a gas at room temperature.
- **N2O3**: This compound is also a gas at room temperature.
- **N2O5**: This compound exists in the solid state at room temperature.

3. **Understanding N2O5**: Dinitrogen pentoxide (N2O5) can exist in an ionic form known as nitronium nitrate (NO2+ NO3-). This ionic solid form is stable at room temperature, confirming that N2O5 is indeed a solid.

4. **Conclusion**: Among the options, the oxide of nitrogen that exists in the solid state at room temperature is **N2O5**.

### Final Answer:
The oxide of nitrogen existing in the solid state at room temperature is **N2O5**.

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