Which oxide of nitrogen is coloured gas

Options

A. `N_2 O`
B. `NO`
C. `N_2 O_5`
D. `NO_2`

Explanation

To determine which oxide of nitrogen is a colored gas, we can analyze the different nitrogen oxides based on their chemical formulas and properties.

### Step 1: Identify the nitrogen oxides
The question provides us with four nitrogen oxides:
1. Di-nitrogen oxide (N2O)
2. Nitrogen monoxide (NO)
3. Nitrogen pentoxide (N2O5)
4. Nitrogen dioxide (NO2)

### Step 2: Analyze the color of each oxide
- **N2O (Di-nitrogen oxide)**: This is commonly known as nitrous oxide, and it is a colorless gas.
- **NO (Nitrogen monoxide)**: This gas is also colorless.
- **N2O5 (Nitrogen pentoxide)**: This compound is a colorless solid at room temperature and does not produce a colored gas.
- **NO2 (Nitrogen dioxide)**: This gas is known for its characteristic brown color.

### Step 3: Conclusion
Based on the analysis, the only colored gas among the nitrogen oxides listed is nitrogen dioxide (NO2), which appears as a brown gas.

### Final Answer
The oxide of nitrogen that is a colored gas is **Nitrogen dioxide (NO2)**.

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