Their historical significance could be related to their use as exposed in the following statement: "Chemical decomposition is exploited in several analytical techniques, notably mass spectrometry, traditional gravimetric analysis, and thermogravimetric analysis." http://en.wikipedia.org/wiki/Chemical_decomposition - - - - [Here is an EXCERPT from the website for you] - - - - Chemical decomposition From Wikipedia, the free encyclopedia Chemical decomposition or analysis is the separation of a chemical compound into elements or smaller compounds. It is sometimes defined as the opposite of a chemical synthesis. Chemical decomposition is often an undesired chemical reaction. The stability that a chemical compound ordinarily has is eventually limited when exposed to extreme environmental conditions like heat, radiation, humidity or the acidity of a solvent. The details of decomposition processes are generally not well defined, as a molecule may break up into a host of smaller fragments. Chemical decomposition is exploited in several analytical techniques, notably mass spectrometry, traditional gravimetric analysis, and thermogravimetric analysis. A broader definition of the term decomposition also includes the breakdown of one phase into two or more phases.[1] he generalized reaction formula for chemical decomposition is: AB → A + B with a specific example being the electrolysis of water to gaseous hydrogen and oxygen: 2H2O → 2H2 + O2 [edit] Additional examples An example of spontaneous decomposition is that of hydrogen peroxide, which will slowly decompose into water and oxygen: 2H2O2 → 2H2O + O2 Carbonates will decompose when heated, a notable exception being that of carbonic acid, H2CO3. Carbonic acid, the "fizz" in sodas, pop cans and other carbonated beverages, will decompose over time (spontaneously) into carbon dioxide and water: H2CO3 → H2O + CO2 Other carbonates will decompose when heated producing the corresponding metal oxide and carbon dioxide. In the following equation M represents a metal: MCO3 → MO + CO2 A specific example of this involving calcium carbonate: