Which oxide of nitrogen is not common pollutant ?

Options

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

Answer

To determine which oxide of nitrogen is not a common pollutant, we can analyze the different nitrogen oxides and their roles in the environment.

### Step 1: Understand Nitrogen Oxides
Nitrogen oxides (NOx) generally refer to a group of gases that include nitrogen monoxide (NO) and nitrogen dioxide (NO2). These gases are produced from combustion processes, such as burning fossil fuels.

**Hint:** Remember that combustion processes are a major source of pollutants.

### Step 2: Identify Common Pollutants
When fossil fuels are burned, nitrogen from the air combines with oxygen to form nitrogen oxides. The most common nitrogen oxides that are considered pollutants are:
- Nitric oxide (NO)
- Nitrogen dioxide (NO2)

**Hint:** Focus on the oxides formed during combustion as they are typically the pollutants.

### Step 3: Consider Other Nitrogen Oxides
There are other oxides of nitrogen, such as:
- Dinitrogen oxide (N2O), also known as laughing gas, which is naturally present in the environment.
- Dinitrogen pentoxide (N2O5), which is less common and is used in chemical reactions, such as nitration.

**Hint:** Think about the natural occurrence and industrial use of different nitrogen oxides.

### Step 4: Eliminate Common Pollutants
From our analysis, we can eliminate NO and NO2 as they are common pollutants resulting from combustion.

**Hint:** Identify which oxides are primarily produced from human activities.

### Step 5: Identify the Non-Pollutant
Among the nitrogen oxides mentioned, N2O (dinitrogen oxide) is naturally occurring and not primarily a pollutant, while N2O5 is used in specific chemical processes but is not commonly found in the atmosphere as a pollutant.

**Hint:** Consider the context of how each oxide is used or produced in the environment.

### Conclusion
The oxide of nitrogen that is not a common pollutant is **dinitrogen pentoxide (N2O5)**.

**Final Answer:** N2O5