Chemical Reactions

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Chemical reactions
Chemical reactions are the heart of chemistry. People have always known that they exist. The Ancient Greeks were the firsts to speculate on the composition of matter. They thought that it was possible that individual particles made up matter.
From the work of 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. These include decomposition, synthesis, combustion, single-displacement, and double-displacement.
Decomposition reactions are reactions in which a substance breaks into smaller parts. As an example, ammonium carbonate will decompose into ammonia, carbon dioxide, and water. Polymerization reactions are reactions in which simpler substances combine to form a complex substance. The thing that makes this reaction unusual is that the final product is composed of hundreds of the simpler reagent (a substance that contributes to a chemical reaction) species. One example is the polymerization of terephthalic acid with ethylene glycol to form the polymer called Dacron, a fiber, or Mylar, in sheet form:
The reaction between iron and chlorine gas is an example of a synthesis reaction. A synthesis reaction is a chemical reaction in which two or more substances react to produce a single product. When two elements react, the reaction is always a synthesis reaction. Another example of a synthesis reaction is 2Na(s) + Cl2(g) à 2NaCl(s). Just as two elements can combine, two compounds can also combine to form one compound. For example, the reaction between calcium oxide and water to from calcium hydroxide is a synthesis reaction. [CaO(g) + O2(g) à 2SO3(g)].
The synthesis reaction between sulfur dioxide and oxygen can be classified also as combustion reaction. In a combustion reaction, oxygen combines with a substance and releases energy in the forum of heat and light. Oxygen can combine in this way wi...