Acid rain is due to

Options

A. formation of oxides of sulphur
B. formation of oxides of nitrogen
C. HCl
D. `HClO_(4)`

Answer

### Step-by-Step Text Solution:

1. **Definition of Acid Rain**: Acid rain refers to any form of precipitation (rain, snow, sleet, or hail) that has a higher acidity than normal due to the presence of acidic components.

2. **Formation of Acid Rain**: The primary cause of acid rain is the formation of acids in the atmosphere. This occurs when certain pollutants are released into the air, leading to chemical reactions that produce acidic compounds.

3. **Key Pollutants**: The main pollutants responsible for acid rain are:
- **Sulfur Dioxide (SO₂)**: Released from industrial processes and burning fossil fuels.
- **Nitrogen Oxides (NOₓ)**: Emitted from vehicle exhaust and power plants.

4. **Chemical Reactions**:
- **Formation of Sulfuric Acid**:
- Sulfur dioxide (SO₂) reacts with oxygen (O₂) in the presence of water vapor (H₂O) to form sulfuric acid (H₂SO₄).
- The overall reaction can be summarized as:
\[ SO₂ + O₂ + H₂O \rightarrow H₂SO₄ \]

- **Formation of Nitric Acid**:
- Nitrogen oxides (NO and NO₂) undergo a series of reactions in the atmosphere, eventually forming nitric acid (HNO₃).
- A simplified version of the reaction is:
\[ NO₂ + H₂O \rightarrow HNO₃ \]

5. **Other Contributing Acids**: Carbon dioxide (CO₂) can also contribute to acid rain by forming carbonic acid (H₂CO₃), though it is a weaker acid compared to sulfuric and nitric acids.

6. **Conclusion**: The acid rain phenomenon is primarily due to the formation of strong acids (sulfuric acid and nitric acid) from the oxides of sulfur and nitrogen, which are released into the atmosphere from human activities.