Why is acid rain acidic?

Answer 1

All plants and animals must have sulphur. Coal and oil are made from old plants and animals that lived millions of years ago. They contain sulphur. Refineries can remove most of the sulphur from most of the oil turned into fuel oil or gasoline. Refineries, factories and power plants can remove the sulphur dioxide from their smokestacks. Frequently they do not. When they do not, the sulphur dioxide turns into sulphur trioxide. The Sulphur trioxide then when the sulphur trioxide runs into a cloud or a drop of water, it turns into sulphuric acid. When it falls to earth, it falls as acid rain. Acid rain is sulphuric acid falling to earth. In North Florida the rain accompanying the first cold front of the fall changed the pH of a swimming pool from 8 to 4. That indicates the amount of acid in the air over the Midwest and Midsouth of the United States. Right now technology exists to rid smokestacks of sulphuric acid.