Brown air and gray air is due to the oxides of

Options

A. Sulfur
B. Nitrogen
C. Carbon
D. Phosphorus

Answer

**Step-by-Step Solution:**

1. **Understanding the Types of Air Pollution:**
- Brown air and gray air are terms used to describe different types of air pollution caused by various chemical compounds.

2. **Identifying Brown Air:**
- Brown air is primarily associated with photochemical smog. This type of smog occurs when nitrogen oxides (NOx) react with hydrocarbons in the presence of sunlight and oxygen.

3. **Chemical Reaction in Brown Air:**
- The reaction involves nitrogen oxides (NOx) and hydrocarbons, which leads to the formation of secondary pollutants, including ozone and other compounds that contribute to the brown color of the air.

4. **Identifying Gray Air:**
- Gray air, often referred to as sulfurous smoke or London smog, is primarily produced from the burning of coal. This results in the release of sulfur dioxide (SO2) and other sulfur compounds into the atmosphere.

5. **Chemical Reaction in Gray Air:**
- The burning of coal releases sulfur compounds, which contribute to the gray appearance of the air. This type of air pollution is characterized by high levels of particulate matter and sulfur oxides.

6. **Conclusion:**
- Therefore, brown air is due to the oxides of nitrogen, while gray air is due to the oxides of sulfur. The correct answer to the question is that brown air is caused by nitrogen oxides and gray air is caused by sulfur oxides.

**Final Answer:**
- Brown air is due to the oxides of nitrogen, and gray air is due to the oxides of sulfur.

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