Chlorofluorocarbons (CFCs) :: essays research papers fc

ChloroflourocarbonsChloroflourocarbons were discovered in the 1920s by Thomas Midgley, anorganic chemist at General Motors Corporation. He was looking for inert, non-toxic, non-flammable compounds with low boiling points that could be utilize asrefrigerants. He found what he was looking for in the form of two compoundsdichlorodifluoromethane (CFC-12) and trichloromonoflouromethane (CFC-11). Inboth compounds, different amounts of chlorine and fluorine are combine withmethane, which is a combination of carbon and hydrogen. These two CFCs wereeventually manufactured by E.I. du Pont de Nemours and company, and, under thetrade name freon, constituted 15% of the market for refrigerator gases.CFCs were the entire answer for cooling refrigerators and airconditioners. They were easily turned into liquidity at room temperature withapplication of just a small amount of pressure, and they could easily thence beturned back into gas. CFCs were completely inert and not poisonous to humans.They became ideal solvents for industrial solutions and hospital sterilants.Another use found for them was to blow liquid plastic into various kinds offoams.In the 1930s, household insecticides were bulky and hard to use, so CFCswere created because they could be kept in liquid form and in an only passablypressurized can. Thus, in 1947, the spray can was born, selling millions ofcans each year. Insecticides were only the first application for CFC spray cans.They soon employed a number of products from deodourant to hair spray. In 1954,188 million cans were sold in the U.S. alone, and four years later, the numberjumped to 500 million. CFC filled cans were so popular that, by 1968, 2.3 one thousand thousand spray cans were sold in America.The hopes of a seemingly perfect refrigerant were diminished in the late1960s when scientists studied the decomposition of CFCs in the atmosphere.What they found was startling. centiliter atoms are released as the CFCs recess, thus destroying the Ozone (O3) atoms in the high stratosphere. Itbecame clear that human usage of CF2Cl2 and CFCl3, and similar chemicals werecausing a negative impact on the chemistry of the high altitude air.When CFCs and other ozone-degrading chemicals are emitted, they mix withthe atmosphere and eventually rise to the stratosphere. CFCs themselves do notactually effect the ozone, but their decay products do. later they photolyzed,the chlorine eventually ends up as reservoir species - they do not themselvesreact with ozone- such as Hydrogen Chloride, HCL, or Chlorine Nitrate, ClONO2.These than further decompose into ozone hurting substances. The simplest is asfollows (How do CFCs Destroy the Ozone) Cl + O3 ----- ClO + O2 ClO + O