Normal rainfall is slightly acidic with a ph of approximately 5.5
This acidity comes from carbon dioxide in the air. carbon dioxide dissolves in rainwater, producing carbonic acid (a weak acid)
Acid rain is more acidic than normal rainwater. It has a pH as low as 3.5 to 3.0. The extra acidity comes from nitrogen oxides and sulfur oxides. These gases are released into the air as pollutants from industry and motor vehicles. These oxides react with water in the air to produce acids, including nitric acid and sulfuric acid. Rainwater containing these acids has more hydrogen ions. It has a lower pH and is more corrosive.
Acid rain can damage statues and buildings, destroy forests and kill fishes in lakes.
