Chemical reactions are the heart of chemistry. People have always known that they exist. The Ancient Greeks were the first to speculate on the composition of matter. They thought that it was possible that individual particles made up matter.
Later, in the seventeenth century, a German chemist named George Ernst Stahl was the first to postulate on chemical reactions. He explained that during combustion, a substance called phlogiston escaped into the air from all substances. Stahl also explained that a burning candle would go out if a candle snuffer was put over it because the air inside the snuffer became saturated with phlogiston. However, Stahl’s theory was contradicted when he said that phlogiston would take away from a substance’s mass or that it had a negative mass. In the eighteenth century, Antoine-Laurent Lavoisier discovered an important detail in the understanding of the chemical reaction combustion: oxygen. He said that combustion was a chemical reaction involving oxygen and another combustible substance, such as wood.
John Dalton discovered the atom in the early nineteenth century. This led to the idea that a chemical reaction is actually the rearrangement of groups of atoms, called molecules. Dalton also stated that the appearance and disappearance of properties are dictated by the atomic composition. He also proposed that a molecule of one substance is exactly the same as any other molecule of the same substance. Joseph-Louis Gay-Lussac added to Dalton’s ideas with the postulate that the volumes of gases that react with each other are related.
Amedeo Avogadro also contributed to the understanding of chemical reactions by stating that all gases at the same pressure, volume, and temperature contain the same number of particles. This idea took a long time to be accepted, but it eventually led to the subscripts used in the formulas for gases. Thanks to the work of Avogadro and many other chemists, we now have a mostly complete knowledge of chemical reactions.
There are now many classification systems to classify the different types of reactions, including decomposition, polymerization, chain reactions, substitute reactions, elimination reactions, addition reactions, ionic reactions, and oxidation-reduction reactions. Bibliography: Chemical Reactions,” Webster Encyclopedia, 1993, Eastman, Richard H.
General Chemistry: Experimental and Theory, Holt, Rhinehart, and Winston Inc., 1970. Pauling, Linus and Peter, Chemistry, W. H. Freeman and Co.
