Acid Rain An Environmental Problem Related to Fossil Fuel Combustion

11 Acid Rain An Environmental Problem Related to Fossil Fuel Combustion  

About 90% of U.S. energy comes from fossil fuel combustion. Fossil fuels include petroleum, natural gas, and coal. Some fossil fuels, especially coal, contain significant amounts of sulfur impurities. During combustion, these impurities react with oxygen to form SO2. In addition, during combustion of any fossil fuel, nitrogen from the air reacts with oxygen to form NO2. The SO2 and NO2 emitted from fossil fuel combustion react with water in the atmosphere to form sulfuric acid and nitric acid. 

I These equations represent simplified versions of the reactions that actually occur. 

These acids combine with rain to form acid rain. In the United States, the problem is greatest in the northeastern portion of the country because many midwestern power plants bum coal. The sulfur and nitrogen oxides produced from coal combustion in the Midwest are carried toward the Northeast by natural air currents, making rain in that portion of the country significantly acidic. 

Rain is naturally somewhat acidic because of atmospheric carbon dioxide. Carbon dioxide combines with rainwater to form carbonic acid. 

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