Acid rain

Definition

Acid rain is precipitation with a lower pH than normal, caused primarily by sulfur dioxide (SO2) and nitrogen oxides (NOx) emissions. These pollutants react with water vapor in the atmosphere to form sulfuric and nitric acids, which fall back to Earth as rain or snow.

5 Must Know Facts For Your Next Test

1. Acid rain can harm aquatic ecosystems by lowering the pH of water bodies, making them inhospitable for many species.
2. It can lead to soil degradation by leaching away essential nutrients like calcium and magnesium.
3. Acid rain also damages forests by weakening trees through nutrient depletion and direct damage to leaves and bark.
4. The primary sources of SO2 and NOx emissions are fossil fuel combustion from vehicles, power plants, and industrial processes.
5. Regions downwind of industrial areas are more likely to experience acid rain due to the transport of pollutants by wind patterns.

Review Questions

• What chemical reactions lead to the formation of acid rain?
• How does acid rain affect aquatic ecosystems?
• What are the main human activities contributing to sulfur dioxide and nitrogen oxides emissions?

Related terms

Eutrophication:

A process where water bodies become enriched with nutrients, leading to excessive growth of algae and depletion of oxygen.

Greenhouse Effect: The trapping of heat in Earth's atmosphere by greenhouse gases, leading to global warming.

Biogeochemical Cycles: Natural processes that recycle nutrients in various chemical forms from the environment to organisms and back again.