In chemistry, Chemical energy is the potential of a chemical substance to undergo a transformation through a chemical reaction or, to transform other chemical substances. Examples include batteries and light bulbs. Breaking or making of chemical bonds involves energy, which may be either absorbed or evolved from a chemical system
Energy that can be released (or absorbed) because of a reaction between a set of chemical substances is equal to the difference between the energy content of the products and the reactants. This change in energy is change in internal energy of a chemical reaction. Where is the internal energy of formation of the reactant molecules that can be calculated from the bond energies of the various chemical bonds of the molecules under consideration and is the internal energy of formation of the product molecules. The internal energy change of a process is equal to the heat change if it is measured under conditions of constant volume, as in a closed rigid container such as a bomb calorimeter. However, under conditions of constant pressure, as in reactions in vessels open to the atmosphere, the measured heat change is not always equal to the internal energy change, because pressure-volume work also releases or absorbs energy. (The heat change at constant pressure is called the enthalpy change; in this case the enthalpy of formation).
Another useful term is the heat of combustion, which is the energy released due to a combustion reaction and often applied in the study of fuels. Food is similar to hydrocarbon fuel and carbohydrate fuels, and when it is oxidized, its caloric content is similar (though not assessed in the same way as a hydrocarbon fuel — see food energy).
In chemical thermodynamics the term used for the chemical potential energy is chemical potential, and for chemical transformation an equation most often used is the Gibbs-Duhem equation.
Chemical potential 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 within a molecule or otherwise. Chemical energy of a chemical substance can be transformed to other forms of energy by a chemical reaction. As an example, when a fuel is burned the chemical energy is converted to heat, same is the case with digestion of food metabolized in a biological organism. Green plants transform solar energy to chemical energy through the process known as photosynthesis, and electrical energy can be converted to chemical energy through electrochemical reactions...
The similar term chemical potential is used to indicate the potential of a substance to undergo a change of configuration, be it in the form of a chemical reaction, spatial transport, particle exchange with a reservoir.
Other articles related to "energy, chemical, chemical energy":
... in its surroundings, generally using energy from light (photosynthesis) or inorganic chemical reactions (chemosynthesis) ... They are able to make their own food, and do not need a living energy or carbon source ... The reduction of carbon dioxide, a low-energy compound, creates a store of chemical energy ...
... Nuclear energy is typically hundreds of thousands or millions of times greater than chemical energy or approximately 1% of the mass energy from the Einstein mass formula ... The mass of a proton is The chemical energy of the hydrogen atom is the separation energy of an electron from a proton ... from the Bohr theory of the hydrogen atom The relative change of mass is the hydrogen chemical energy divided by its mass, here the proton mass It is so small as to be unmeasurable ...
... Chemical potential 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 within a molecule or otherwise ... Chemical energy of a chemical substance can be transformed to other forms of energy by a chemical reaction ...
Famous quotes containing the words energy and/or chemical:
“The scholar may be sure that he writes the tougher truth for the calluses on his palms. They give firmness to the sentence. Indeed, the mind never makes a great and successful effort, without a corresponding energy of the body.”
—Henry David Thoreau (18171862)
“We do not want actions, but men; not a chemical drop of water, but rain; the spirit that sheds and showers actions, countless, endless actions.”
—Ralph Waldo Emerson (18031882)