Chemical energy, one of the ways in which energy manifests itself in reality, is always associated with matter and will manifest itself when a specific modification occurs in it. This can occur in the presence of heat sources, or other substances, with which there is an exchange of particles that generally produce heat, light or other forms of energy derived from the reaction.
In this way, chemical energy is a form of potential energy, contained in chemical substances, which, once involved in a reaction, are transformed into other usable forms of energy. This is how, for example, the combustion processes of gasoline and other fossil hydrocarbons work.
The use of this form of energy may be relatively new in the history of mankind, but not in the world: since time immemorial, life has taken advantage of photosynthesis and chemosynthesis, among other processes to obtain energy, to take advantage of molecular potential Of the mattery.
What is chemical energy for?
Gasoline converts chemical energy into kinetic energy when it is used to move a vehicle.
Remember that according to the Principle of Conservation of Energy, the latter can be transformed into other types of energy, but it cannot be created or destroyed. And this chemical energy is a form of potential energy, which therefore serves to transform into other forms of energy that have practical applications in human life, such as light, thermal energy, kinetics, etc., to perform work .
For example, gasoline is used to convert chemical energy into kinetic energy when we use it to move a vehicle, such as a motorcycle.
Advantages of chemical energy
Chemical energy has the following advantages:
- It has a high performance. Large amounts of matter are not necessary to obtain energy from its molecules.
- Allows you to change the subject. These chemical reactions not only produce energy, but also new forms of matter that, in many cases, can be perfectly used to obtain new materials.
- It allows us to take advantage of residual materials. As in the case of bioethanol or other biofuels, which are formed from organic matter that, in other cases, would be uselessly decomposed and would be waste.
Disadvantages of chemical energy
- Fossil fuels expel toxic gases into the atmosphere.
- It has by-products. They can often be polluting substances, as in the case of fossil fuels that expel toxic gases into the atmosphere.
- Requires constant input. As it is used after the chemical reaction, maintaining the rate of chemical burning or consumption requires more organic matter to fuel the reaction.
Chemical energy of food
The food we consume daily is an ideal example of chemical energy and its use. These foods contain different organic substances necessary to provide energy to our bodies, as well as fuel for vehicle engines.
These organic substances are broken down in our body into glucose (C6H12O6), the molecule whose oxidation during respiration releases large amounts of cellular heat energy (calories) to keep the body short-circuited. The excess glucose is thus converted into fat: a reserve in case we need it later.
This is an example of the use of the chemical energy of glucose contained in food to produce mechanical energy (in movement, keeping the feet), sound (speaking), electrical (electrical energy neurons that allow us to think), etc …
Examples of chemical energy
Some examples are the following:
Gasoline, diesel, all petroleum-derived fuels are made up of sequences based on hydrogen and carbon molecules, the bonds of which can break in the presence of oxygen (combustion), releasing large amounts of energy violently.
The foods we eat:
As we explained above, the glucose contained in food is oxidized in our body and, by breaking its bonds, we obtain a useful caloric load to maintain the body’s energy.
Many living organisms have the ability to produce light with their bodies, which is known as bioluminescence. This light energy comes from the chemical energy stored in their bodies.
Space travel rockets fly by the controlled reaction between various high-energy chemical substances (hydrogen and liquid oxygen, usually) that are converted into huge amounts of kinetic energy.
How does chemical energy work?
The operation of this energy is given by chemical reactions that are accompanied by a release or absorption of energy. Surrounded by atoms and molecules, there is a rearrangement of electrons and protons to produce electrical charges.
The energy released or absorbed can take the form of electrical, light, mechanical energy, etc., but the most common form is through heat. These chemical reactions can be classified as exothermic or endothermic, depending on the release or absorption of heat, respectively.
On the other hand, the heat that is exchanged is known as the heat of reaction and its value is specific for each reaction. All matter stored in chemical energy, known as energy content. Chemical energy always transforms or changes matter where it was kinetic.
Characteristics of chemical energy
- It is contained in matter.
- When a chemical reaction occurs, there is a transformation of matter into another new compound.
- There may be heat release or absorption.
- It is a reaction that occurs between the atoms that make up matter.
- The bonds between the atoms are broken and they are transformed into new substances.
- If the chemical reaction does not occur, the chemical energy is not released or absorbed.
Examples of chemical energy
Plants obtain energy from the chemical reactions that occur within them. The sun, CO2, enzymes and organic substances that obtain oxygen and energy participate. This energy is the result of the chemical reaction contained in the molecules of the acting substances. The plant releases this energy for its benefit and performs its vital maintenance.
As in the previous example, animals use oxygen and glucose. To maintain the cycle, it is necessary to release water, CO2 and obtain energy. Through this chemical process, the animal kingdom is kept alive, including humans.
When a vehicle engine is started, the hydrocarbon used as fuel undergoes a sequence of controlled ignitions and detonations that allow movement. Fuel stores energy in carbon and hydrogen atoms. Once broken, they transform into different compounds and energy is released.
Bacteria, fungi and microorganisms that take decomposed organic matter as food obtain the energy necessary for the fermentation of starches and sugars. From this chemical reaction, alcohols or any other product generated by the decomposition of organic molecules are obtained.
Batteries and batteries:
Batteries used in controls, cell phones, or automobiles have acids and metals that cause a controlled chemical reaction. The result is an immediately usable amount of electricity.
Although it is a completely separate branch and a form of energy as such, it can be said to be part of chemical energy. The origin of nuclear reactions is in a series of chain reactions caused by humans. This occurs in elements manipulated in the laboratory, such as uranium and hydrogen. These are chemically forced to fuse or fuse the atoms, releasing large amounts of energy.