Almost every phenomena of nature, be it geographical or biological, is in some or the other way, a manifestation of energy. Energy transformation forms a fundamental part of all biological processes. In physics, energy assumes a significant importance as it a physical quantity that can be assigned to any particle or object that is in a state of rest or motion. Similarly, in chemistry, there are abundant examples in which this form of energy is stored in various materials or that is a part of various chemical reactions, is transformed into different forms of energy. Gravitational, potential, kinetic, mechanical, electrical, wind energy, magnetic, and nuclear energy are various other types of energy.
An Introduction to Chemical Energy
- It is an inherent energy in the atoms and molecules of a substance. Simply stated, every compound is made of atoms and molecules. Each of these atoms and molecules are held by strong or weak covalent and ionic bonds.
- All types of chemical bonds have specific energy, and this is the energy released when the bonds are broken in a chemical reaction.
- In certain chemical reactions, heat energy is released after the reaction completes. These are known as exothermic reactions, and in such reactions, the energy required for the reaction to occur is less than the total energy released.
- On the other hand, there are certain chemical reactions, which absorb heat from its surroundings to carry out the reaction. These are known as endothermic reactions.
- There are numerous examples of this form of energy in which both reactions are endothermic or exothermic.
Examples of Chemical Energy
- Almost all reactions involving combustion of chemical compounds or chemical elements, photosynthesis, cellular respiration, cells, and batteries are perfect examples of chemical energy.
- Plants, for instance create food by the process of photosynthesis, which is probably one of the most studied examples of this kind of energy. Plants and trees absorb solar energy and use it to turn carbon dioxide and water present in the atmosphere to oxygen and sugar (sucrose, fructose, etc).
- Just like fats in animals are used for storing energy, the sugar molecules produced by the process of photosynthesis are stored by plants for gaining energy. These sugar compounds that constitute an integral part of trees, plants, fruits and vegetables are the sources of chemical energy in plants and trees. When animals feed on the fruits and vegetables and other parts of plants, these sugar molecules provide energy to the animals.
- Another example would involve the sugar molecules present in the molecular process of cellular respiration.
- The organic food consumed by humans contains sugar and other molecules that are further broken down into carbon dioxide, water, and Adenosine Triphosphate (ATP). ATP, as many of us must have read in our school biology courses, is an important chemical that helps in transferring chemical energy in the body for metabolic processes.
- Combustion processes also known as burning comprises various examples of chemical energy.
- Burning of wood, charcoal and other items lead to release of this energy into the atmosphere, for instance, burning fossil fuels.
- These reactions are accompanied by release of light and heat energy. One of the simplest and most evident examples is batteries, that we use in our daily life. Batteries contain chemicals like zinc and lead, whose energy is converted into electrical energy after electrical connection is established between two leads of the battery.
These examples are the easiest and the most simplest to understand. They are considerably simpler to explain when chemical energy is a novelty to the layman.