Energy and Reactions * Energy must be added to break bonds. * Many forms of energy can be used to break bonds: * Heat * Electricity * Sound * Light * Forming bonds releases energy * Example: when gasoline burns, energy in the form of heat and light is released as the products of the isooctane-oxygen reaction and other …show more content…
* The total energy that exists before the reaction is equal to the total energy of products and their surroundings. * An exothermic reactions is a chemical reaction in which heat is released to the surroundings * An endothermic reaction is a chemical reaction that absorbs heat. * A synthesis reaction is a reaction in which two or more substances combine to form a new compound * Synthesis reactions have the following general form: A + B AB * Example: in the following synthesis reaction, the metal sodium reacts with the chlorine gas to form sodium chloride, or table salt. * 2Na+Cl2 2NaCl * A decomposition reaction is a reaction in single compound beaks down to form two or more simpler substances. * Decomposition reactions have the flowing form: AB A+B * Example: The following shows the decomposition of water * 2H2o 2H2+O2 * Electrolysis is the process in which an electric current is used to produce a chemical reaction, such as the decomposition of water.
Classifying Reactions * A combustion reaction is the oxidation reaction of an organic compound, in which heat is