Chemical energy is the potential of a chemical to undergo a transformation through a chemical reaction or to transform into other chemicals. Forming or breaking chemical bonds involves energy. This energy can be absorbed or evolved from a chemical system.
The energy that can be released (or absorbed) by a reaction between a set of chemical substances is equal to the difference between the amount of energy of the products and the reactants. This change in energy is called the internal energy of a chemical reaction.
The internal energy change of a process is equal to the change of heat if it is measured under constant volume conditions, as in a calorimeter. However under conditions of constant pressure measured heat is not always equal to the internal energy change. The change of heat at constant pressure is called enthalpy change.
Another useful term is the heat of combustion, which is the energy released in the combustion reaction and often applied to the study of fuels.
In thermodynamic chemistry the term used for potential energy is chemical potential, and by chemical transformation the Gibbs-Duhem equation is often used.
Since the strength of chemical bonds is associated with the distance between the chemical species (in fact the stronger chemical bonds have the chemical elements involved in the closer bond), the chemical energy depends on the mutual position of the particles Constitute a substance.
Thus, chemical energy is the energy stored in chemical bonds and is largely attributable to the sum of the potential energy of the electrostatic interactions of the charges present in the ponderable matter plus the kinetic energy of the electrons.
If you have a "zero level" of chemical energy that where there are no chemical bonds, the chemical energy is negative.
Resonance is a chemical-structural phenomenon that greatly influences chemical energy in the sense stabilizer. The reactivity and kinetics of the various compounds suffer from differences in chemical energy.
Chemical energy occurs in the course of transformations that take place at the level of molecules.
Potential chemical energy
Potential chemical energy is a form of potential energy related to the structural arrangement of atoms or molecules. This arrangement may be the result of chemical bonds between molecules. The chemical energy of a substance can be transformed into other forms of energy by chemical reaction.
The similar term of chemical potential is used to indicate the potential of a substance to undergo a change of configuration, in the form of chemical reaction, spatial transport, particle exchange with a reservoir.
Examples of chemical energy
Here are some examples of chemical energy:
- Nuclear energy. In nuclear reactions of fission or fusion are generated chemical alterations in atoms that are transformed into chemical energy.
- Combustion of a fuel. An example of this case is when we burn a fuel and obtain thermal energy in the form of heat.
- Digestion by a living organism. Food, through certain reactions in the stomach become chemical energy for the body.
- Photosynthesis. Green plants derive energy by transforming solar energy into chemical energy in photosynthesis, electrical energy can be converted into chemical energy through electrochemical reactions.
Last review: November 25, 2016Back