Main pollutant from automobile exhaust is :

Options

A. `CO`
B. `CO_(2)`
C. `NO`
D. hydrocarbons

Answer

To determine the main pollutant from automobile exhaust, we can analyze the common components released during the combustion of fuel in vehicles. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify Common Pollutants in Automobile Exhaust
Automobile exhaust typically contains several pollutants, including:
- Carbon monoxide (CO)
- Carbon dioxide (CO2)
- Nitrogen oxides (NOx, including NO and NO2)
- Hydrocarbons (unburned fuel)

### Step 2: Understand the Composition of Exhaust Gases
When fuel is burned in an automobile engine, the combustion process produces various gases. The main products of complete combustion are carbon dioxide (CO2) and water vapor (H2O). However, incomplete combustion can lead to the formation of carbon monoxide (CO) and unburned hydrocarbons.

### Step 3: Analyze the Proportions of Pollutants
According to the information provided:
- Nitrogen dioxide (NO2) is released in significant amounts (around 60-70%).
- Carbon dioxide (CO2) is released in smaller amounts (around 14%).
- Water vapor (H2O) is also present (around 10%).
- Carbon monoxide (CO) is a notable pollutant but is not the largest in terms of volume.

### Step 4: Determine the Main Pollutant
Based on the analysis, while carbon monoxide (CO) is a harmful pollutant, the main pollutant in terms of volume and environmental impact from automobile exhaust is nitrogen dioxide (NO2). However, if we are looking for the most commonly recognized pollutant in terms of toxicity and public health impact, carbon monoxide (CO) is often highlighted.

### Conclusion
The main pollutant from automobile exhaust is carbon monoxide (CO).

### Final Answer
The main pollutant from automobile exhaust is **CO (Carbon Monoxide)**.

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