Chemical Energy - Glossary Definition

Chemical energy is the energy contained in the internal structure of an atom or molecule. It is a measure of a substances capacity to transform into another substance via a chemical reaction. This energy could be in the electronic structure of a single atom or in the bonds between atoms in a molecule. Chemical energy is converted into other forms of energy by chemical reactions. Examples of substances that contain chemical energy include: WoodFoodGasolineBatteries Chemical energy is released or absorbed as chemical bonds are broken and reform. It is a misconception that a substance always releases more energy than it absorbs! Chemical energy is calculated as the difference between the energy of the products and reactants. This may be measured using a calorimeter or calculated based on the bond energies of the chemical bonds. Reference Schmidt-Rohr, K (2015). Why Combustions Are Always Exothermic, Yielding About 418 kJ per Mole of O2.  J. Chem. Educ.  92: 2094–2099.