In fact, since at least as far back as Aristotle, the basic formula for comedy has had more to do with conventions and expectations of plot and character than with a requirement for lewd jokes or cartoonish pratfalls. In essence: A comedy is a story of the rise in fortune of a sympathetic central character.
The Acid Rain Problem. Carbon dioxide in the air can dissolve in rain water to form carbonic acid, H 2 CO 3. CO 2 + H 2 O H 2 CO 3. Carbonic acid is a weak acid. It partially ionises to form hydrogen ions. H 2 CO 3 H + + HCO 3 -. The hydrogen ions from carbonic acid give natural rain water a slightly acid pH value of 5.6.
Sources of Acid Rain. Acid rain is caused by a chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air. These substances can rise very high into the atmosphere, where they mix and react with water, oxygen, and other chemicals to form more acidic pollutants, known as acid rain. Sulfur dioxide and nitrogen oxides dissolve very easily in water and can be carried very far by the wind. As a result, the two compounds can travel long distances where they become part of the rain, sleet, snow, and fog that we experience on certain days. Human activities are the main cause of acid rain.