asprin
ASPIRIN Since 400BC physicians prescribed aspirin in its unrefined state to alleviate pain. Aspirin originated from the leaves and bark of the willow tree, rich in salicin, natural compound similar to acetylsalicylic acid, and the chemical name for aspirin. The story of aspirin is well documented by Heathcock, A (1998. He states that in 1897, when Felix Hoffmann, a German chemist with “Friedrich Bayer and Company”, modified salicylic acid to acetylsalicylic acid to make it less harsh on the stomach and relieve his father's rheumatism. Aspirin was born: “a” for acetyl, “spir” for the spirea plant (which yields salicin) and finally “in” common suffix for medication. Aspirin is one of the first drugs to come into common usage and the most widely used, in the world today. Indeed, approximately 35,000 metric tonnes are produced and consumed annually, enough to make over 100 billion standard aspirin tablets every year It is an anti-inflammatory painkiller, reducing inflammation, fever as well as the risk of heart attacks and Strokes. Aspirin has been around for more than a century now. Its synthesis, chemical properties, uses and impact of the environment are the main topics of this paper. Aspirin has a chemical formula of C9H8O4. It is prepared by chemical synthesis from salicylic acid to acetylation with acetic anhydride. The raw materials needed to make the chemical, as identified by Carey, A (1992), are as follow: Phenol C6H5-OH, naturally occurs in pinewood and pine needles, in the urine of herbivores (phenol sulphate) and in coal tar. Synthetic production has however become predominant and involves the decomposition of cumene hydroperoxide with acetone forming as by-product. Sodium hydroxide NaOH, colourless solution produced by the rapid reaction between sodium metals and water molecules. It is also prepared industrially from sodium chloride by the electrolysis of concentrated brine (aqueous sodium chloride), using inert electrodes. Carbon Dioxide CO2, occurs in the products of combustion of all carbonaceous fuels and can be recovered from them in a variety of ways. CO2 is also a product of animal metabolism and is important in the life cycles of both animals and plants. It is present in the atmosphere in small quantities (0.03%, by volume unit). Acetic Anhydride CH3COOCOCH3, is formed by the dehydration (water removal) reaction between two acetic acids. Acetic acids result from the fermentation of grapes or other organic substances, yielding ethanol, which oxidises in the presence of a biological or chemical catalyst to give acetic acid. Hydrogen H, colourless, odourless and least dense gas is obtained from mines, oils and gas wells. It is produced by the reaction of metals such as zinc or magnesium with an acid or electrolysis of water in the laboratory. However, that method is very expensive so not cost effective on an industrial scale, where Hydrogen is prepared by two processes: the "water gas reaction" using coke and water and the steam reforming process using natural gas and water.