Q. Acid precipitation is now regarded as a serious problem in some European and Asian countries. Which of the following was its major cause or source?
Answer: emissions of sulphur oxides and nitrogen oxides from thermal power plants and burning of fossil fuels; these oxides dissolve in atmospheric water vapour and fall back on earth as acid rain
Notes: The main chemicals in air pollution that create acid rain are sulfur dioxide (SO2) and nitrogen (NOx). Acid rain usually forms high in the clouds where sulfur dioxide and nitrogen oxides react with water, oxygen, and oxidants. this mixture forms a mild solution of sulfuric acid and nitric acid.