Acid Rain

Acid rain refers to a mixture of wet and dry deposition of chemical compounds from the atmosphere containing higher than normal amounts of nitric acid and sulfuric acid (HNO3 and H2SO4, respectively). Rain with a pH of 5.0 or stronger is considered acidic, which is slightly more acidic than clean or unpolluted rainwater (around 5.2–5.6). Extreme cases have been measured at a pH of between 3.0 and 4.5. Pure, unpolluted water has a pH of around 7.0. The phenomenon of acid rain and deposition has resulted in geographically and regionally pronounced effects, leading in some cases to dead lakes, fish, and trees, and damaged soils, crops, and national monuments in many countries. Nitric acid and sulfuric acid also damage human health. Concern with this problem ...