Question

Which oxides cause acid rains?

• A. Sulphur dioxide
• B. Nitrogen oxide
• C. Carbon dioxide
• D. Both A and B

Answer 1

Answer: (D)

Both A and B

Air pollution from burning of fossil fuels is the major cause of acid rain. The main chemicals in air pollution that create acid rain are sulfur dioxide ($S{O}_2$) and nitrogen oxides. 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. Sunlight increases the rate of most of these reactions. Rainwater, snow, fog, and other forms of precipitation containing those mild solutions of sulfuric and nitric acids fall to earth as acid rain.