Decomposition Reactions

chemical reactions in which two or more substances are formed from a single substance. For example, mercuric oxide decomposes into mercury and oxygen upon heating: 2HgO = 2Hg + O₂; silver chloride decomposes to yield silver and chlorine upon exposure to light: 2AgCl = 2Ag + Cl₂. An industrially important decomposition reaction is the pyrolysis of many hydrocarbons and their derivatives.