Acid Rain and Environmental Chemistry
Pollutants lower rain pH and harm ecosystems.
About this topic
Acid rain is precipitation with a pH below about 5.6, the natural acidity of rain from dissolved carbon dioxide. It is caused mainly by sulfur dioxide and nitrogen oxides from burning fossil fuels, which react with water in the air to form sulfuric and nitric acids: SO2 + O2 + H2O → H2SO4, and NO2 + H2O → HNO3.
Power stations, vehicles and smelters release these gases, which can travel hundreds of kilometres before falling as rain, snow or dry deposition. The acid damages forests, acidifies lakes so that fish and amphibians die, leaches aluminium from soil, and corrodes buildings, statues and bridges: calcium carbonate in marble and limestone reacts with acid to give calcium sulfate, carbon dioxide and water. Lakes on limestone soil are buffered and resist acidification, but those on granite are vulnerable.
Solutions include scrubbers (flue gas desulfurisation using limestone), catalytic converters in cars, low-sulfur fuels and renewable energy. In regions that adopted these measures, sulfur dioxide emissions fell significantly, and lakes recovered. Liming lakes with calcium oxide is a temporary treatment.
Misconceptions: that normal rain has pH 7 (it is naturally mildly acidic), and that acid rain burns skin; it is typically no more acidic than vinegar-diluted water, but its long-term ecological damage is serious. Also, acid rain is distinct from the ozone hole and global warming, which have different causes.
Key ideas
- SO₂ and NOₓ form acids
- Corrodes stone and kills fish
- Scrubbers and catalytic converters help
Quick check
Use cases: where Acid Rain and Environmental Chemistry helps
- Homework: review the key idea behind Acid Rain and Environmental Chemistry before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Acid Rain and Environmental Chemistry without notes.
- Visual learning: play with the interactive lab to see how Acid Rain and Environmental Chemistry changes when you adjust its inputs.
- Teaching a friend: explain Acid Rain and Environmental Chemistry in your own words, then compare your version with the key ideas.
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Frequently asked questions
What is Acid Rain and Environmental Chemistry?
Pollutants lower rain pH and harm ecosystems.
What will I learn in Acid Rain and Environmental Chemistry?
SO₂ and NOₓ form acids. Corrodes stone and kills fish. Scrubbers and catalytic converters help.
Is Acid Rain and Environmental Chemistry part of Chemistry?
Yes. It is one of 150 Chemistry topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Acid Rain and Environmental Chemistry lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Acid Rain and Environmental Chemistry?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.