Acid Rain :: essays research papers fc

Acid RainWhat is acid rain? Acid rain is not a recent phenomenon. In the 17th century, scientists noted the ill effects that industry and acidic pollution was having on vegetation and people. However, the term acid rain was not coined until two centuries by and by when Angus Smith published a book called Acid Rain in 1872 ( Zumdahl 173).Acidic pollutants can be deposited from the atmosphere to the Earths surface in wet and dry forms. The vernacular term to describe this process is acid deposition. The term acid precipitation is used to specifically describe wet forms of acid pollution that can be found in rain, sleet, snow, fog, and cloud vapor. An acid can be defined as any substance that when dissolved in water dissociates to yield grim hydrogen ions. The acidity of a substances dissolved in water is commonly measured in terms of pH. According to this measurement scale solutions with pHs less than 7 are described as being acidic, while a pH greater than 7.0 is considered alkali ne. Precipitation normally has a pH between 5.0 to 5.6 because of natural atmospheric reactions involving carbon dioxide. Precipitation is considered to be acidic when its pH falls below 5.6. Some sites in eastern North America have precipitation with pHs as low as 2.3 or about 1000 times more acidic than natural ( Zumdahl 171).     One of the main causes of acid rain is sulphur dioxide. raw(a) sources, which emit this gas, are volcanoes, sea spray, rotting vegetation and plankton. However, the burning of fossil fuels, such(prenominal) as coal and oil, are largely to be blamed for roughly half of the emissions of this gas in the world. When sulphur dioxide reaches the atmosphere, it oxidizes to first form a sulphate ion. It then becomes sulphuric acid as it joins with hydrogen atoms in the air and falls back down to earth. Oxidation occurs mostly in clouds and especially in heavily polluted air where other compounds such as, ammonia and ozone service to cata lyze the reaction, converting more sulphur dioxide to sulphuric acid.      One of the direct effects of acid rain is on lakes and its aquatic ecosystems. There are several routes by means of which acidic chemicals can enter the lakes. Some chemical substances exist as dry particles in the air while others enter the lakes as wet particles such as rain, snow, sleet, hail, dew or fog. In addition, lakes can almost be thought of as the "sinks" of the earth, where rain that falls on land is drained through the cloaca systems eventually makes their way into the lakes.