Which oxide of nitrogen is coloured gas?

Options

A. `N_2O`
B. `NO`
C. `N_2O_5`
D. `NO_2`

Answer

To determine which oxide of nitrogen is a colored gas, we can follow these steps:

### Step 1: Identify the Oxides of Nitrogen
First, we need to list the common oxides of nitrogen. The main oxides are:
1. Nitrous oxide (N2O)
2. Nitric oxide (NO)
3. Nitrogen dioxide (NO2)
4. Dinitrogen tetroxide (N2O4)
5. Nitrogen pentoxide (N2O5)

### Step 2: Analyze the Color of Each Oxide
Next, we will analyze the color of each oxide:
- **N2O (Nitrous oxide)**: This is a colorless gas.
- **NO (Nitric oxide)**: This is also a colorless gas.
- **NO2 (Nitrogen dioxide)**: This is a dark reddish-brown gas.
- **N2O4 (Dinitrogen tetroxide)**: This is colorless in its pure form but can appear yellowish in higher concentrations.
- **N2O5 (Nitrogen pentoxide)**: This is a colorless solid at room temperature.

### Step 3: Identify the Colored Gas
From the analysis, we see that:
- The only oxide of nitrogen that is colored is **NO2 (Nitrogen dioxide)**, which is a dark reddish-brown gas.

### Conclusion
Thus, the oxide of nitrogen that is a colored gas is **Nitrogen dioxide (NO2)**.

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