Formation of Acid Rain
Acid rain is formed when carbon dioxide dissolves in raindrops. Here's how it happens:

Dissolution of Carbon Dioxide
- Carbon dioxide, a gas present in the atmosphere, dissolves in rainwater to form carbonic acid.
- The chemical reaction can be represented as:
CO2 (gas) + H2O (liquid) → H2CO3 (carbonic acid)

Release of Sulfur Dioxide and Nitrogen Oxides
- In addition to carbon dioxide, sulfur dioxide (SO2) and nitrogen oxides (NOx) emitted from burning fossil fuels can also combine with rainwater to form sulfuric acid and nitric acid, respectively.
- These acids contribute to the acidity of rainwater, leading to acid rain.
- The chemical reactions involving sulfur dioxide and nitrogen oxides are:
SO2 + H2O → H2SO3 (sulfurous acid)
2NO2 + H2O → HNO3 + HNO2 (nitric acid + nitrous acid)

Environmental Impact
- Acid rain can have detrimental effects on the environment, including the acidification of soil and water bodies, damage to vegetation, and corrosion of buildings and infrastructure.
- It can also impact aquatic life by altering the pH of water bodies and harming aquatic organisms.
In conclusion, acid rain is primarily formed when carbon dioxide, sulfur dioxide, and nitrogen oxides react with rainwater to produce acidic compounds. Understanding the formation of acid rain is crucial for addressing its environmental consequences and mitigating its harmful effects.