Burning fuels such as diesel and coal release sulphur dioxide. It has corrosive effects and is also suffocative in nature. Acid rain is another serious problem which damages old monuments such as the Taj Mahal.
Oxides of nitrogen and sulphur are present in smoke emitted by vehicles. These combine with water vapour present in the atmosphere to form acids which are responsible for damaging soil, crops and buildings. This is the reason why the eco-friendly fuel CNG, is now being widely used in commercial vehicles, in India. The by-product of combustion of CNG is not harmful to the environment.
Acid rain which is very harmful for crops, buildings and soils is formed by dissolving

Options

A. sulphur and nitrogen oxides released during the combustion of fuels
B. hydrogen and water released during combustion of fuels
C. metal oxides present in the soil
D. unburnt carbon particles released during combustion of fuels.

Explanation

To solve the question regarding the formation of acid rain and its harmful effects, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Combustion**:
- When fuels such as diesel and coal are burned, they release various gases, including sulfur dioxide (SO₂) and nitrogen oxides (NOx).

**Hint**: Remember that combustion is a chemical reaction that typically involves oxygen and produces heat and light.

2. **Formation of Acid Rain**:
- The sulfur dioxide (SO₂) and nitrogen oxides (NOx) released during combustion can react with water vapor in the atmosphere.
- For example, nitrogen dioxide (NO₂) can react with water (H₂O) to form nitric acid (HNO₃):
\[ 2 NO_2 + H_2O \rightarrow HNO_3 + HNO_2 \]
- Similarly, sulfur trioxide (SO₃) can react with water to form sulfuric acid (H₂SO₄):
\[ SO_3 + H_2O \rightarrow H_2SO_4 \]

**Hint**: Look for the chemical reactions that occur when pollutants mix with water to form acids.

3. **Effects of Acid Rain**:
- Acid rain, which consists of these acids (nitric and sulfuric), can have harmful effects on the environment. It can damage crops, buildings, and soil.
- The acidity can lead to the deterioration of structures, such as historical monuments, and can harm plant life by altering soil pH.

**Hint**: Consider how acid rain interacts with different materials and ecosystems.

4. **Eco-Friendly Alternatives**:
- Due to the harmful effects of acid rain, there is a shift towards using eco-friendly fuels like CNG (Compressed Natural Gas), which produces fewer harmful emissions when burned.

**Hint**: Think about the benefits of using cleaner fuels and how they can reduce environmental pollution.

### Conclusion:
Acid rain is formed when sulfur dioxide and nitrogen oxides from fuel combustion react with water vapor in the atmosphere, leading to the formation of harmful acids like sulfuric and nitric acid. This phenomenon poses significant risks to agriculture, infrastructure, and the environment, prompting the use of cleaner fuels like CNG.