Chemical Reactions Essay Example For Students

Chemical Reactions Essay Chemical reactions are the heart of chemistry. People have always known thatthey exist. The Ancient Greeks were the first to speculate on the composition ofmatter. They thought that it was possible that individual particles made upmatter. Later, in the Seventeenth Century, a German chemist named George ErnstStahl was the first to postulate on chemical reaction. He said that a substancecalled phlogiston escaped into the air from all substances during combustion. Heexplained that a burning candle would go out if a candle snuffer was put over itbecause the air inside the snuffer became saturated with phlogiston. Stahl alsosaid that phlogiston will take away from a substances mass or that it had anegative mass, which contradicted his original theories. In the EighteenthCentury Antoine-Laurent Lavoisier, in France, discovered an important detail inthe understanding of the chemical reaction combustion, oxigine (oxygen). He saidthat combustion was a chemical reaction involving oxygen and an other combustiblesubstance, such as wood. John Dalton, in the early Nineteenth Century,discovered the atom. It led to the idea that a chemical reaction was actuallythe rearrangement of groups of atoms called molecules. Dalton also said that theappearance and disappearance of properties meant that the atomic compositiondictated the appearance of different properties. He also came up with idea thata molecule of one substance is exactly the same as any other molecule of thesame substance. People like Joseph-Lois Gay-Lussac added to Daltons ideas withthe postulate that the volumes of gasses that react with each other are related. Amedeo Avogadro also added to the understanding of chemical reactions. He saidthat all gasses at the same pressure, volume and temperature contain the samenumber of particles. This idea took a long time to be accepted. His ideas leadto the subscripts used in the formulas for gasses. From the work of these andmany other chemists, we now have a mostly complete knowledge of chemicalreactions. There are now many classification systems to classify the differenttypes of reactions. These include decomposition, polymerization, chainreactions, substitute reactions, elimination reactions, addition reactions,ionic reactions, and oxidation-reduction reactions. BibliographyChemical Reactions, Webster Encyclopedia. 1993. Eastman, RichardH., General Chemistry: Experimental and Theory, Holt, Rhinehart, and WinstonInc., 1970 Pauling, Linus and Peter, Chemistry, W. H. Freeman and Co.,