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Acid Rain



Acid rain is considered by many people to be one of the most serious environmental problems of our time. It is a global problem that is gradually affecting our world. The term acid rain was coined by Angus Smith when he wrote about industrial pollution in England. Some rain is naturally acidic because of the carbon dioxide (CO2) in air that dissolves with rain water and forms a weak acid. This kind of acid in rain is actually beneficial because it helps dissolves minerals in the soil that both plants and animals need. Recently there has been some concern that the acidity of rain caused by man has increased over the last several decades. Acid rain attacks wildlife, crops and lakes. It can cause the death of forests and damage buildings and monuments. It is even harmful for human beings. Acid rain is caused by pollution. Pollutants like sulphur dioxide and nitrogen oxide stay in the atmosphere and eventually react with the moisture in the air. When this polluted moisture falls to the ground, it is called acid rain. The source of these pollutants is not only from burning fossil fuels, but from both motor vehicle and chemical manufacturing exhaust. Sulphur dioxide is unlike other kinds of acid pollution because it does not react with moisture until it has been taken long distances by the wind. Even worse is that rain and snow are not the only ways the environment can be damaged by air pollution. Dry fallout from sulphur dioxide can still affect the environment. Although places like the Adirondacks in New York have been seriously damaged because the lime in their soil is so easily dissolved by acid rain, there are ways to bring it under control. When both the United States and Canada began reducing the amount of sulphur dioxide released into the air, fresh water lakes and ponds in parts of Canada showed some improvement.


Using a special kind of paper called litmus paper, you will test some common solutions. Litmus or pH paper is an indicator paper that turns different colors depending how acidic or basic a solution is. Materials
  • Measuring cups
  • Water
  • 4 glasses or jars
  • Lemon juice
  • Ammonia
  • Baking Soda
  • Cola soft drink
  • Litmus paper
1. Put 250 ml of water in each glass or jar. Label the jars A, B, C and D. 2. Add 10 ml of lemon juice in A; 10 ml of ammonia in B; one gram of baking soda to C, and 10 ml of cola to D. 3. Dip a separate piece of litmus paper into each container. Compare your results to the color chart included with your litmus paper.


  • Gay, Kathleen. Acid Rain. New York: Franklin Watts Co., 1983.
  • McCormick, John. Acid Rain. New York: Glouchester Press, 1986.
  • Miller, Christian C. and Berry, Lousie A. Acid Rain: A Sourcebook for Young People. New York: Simon and Schuster, 1986.
  • USA Today, Earth Today, Volume 5. Number 1. Washington, DC: Gannett, 1990.