What is Chemical Energy? - Definition & Examples
- 0:08 What is Chemical Energy?
- 0:55 Application of Chemical Energy
- 1:54 Chemical Energy in Everyday Life
- 3:46 Endothermic and Exothermic Reactions
- 4:47 Lesson Summary
This lesson describes chemical energy as a type of potential energy stored in chemicals, such as sugar and gasoline. The lesson discusses how energy is transferred from solar energy to chemical energy by plants and how gasoline is a source of chemical energy used to move cars.
What Is Chemical Energy?
Energy is the ability to do work, where work is movement of an object by some force. We use energy every day, and energy comes in different forms. Chemical energy is energy that is stored in chemicals, such as sugar and gasoline. As chemical energy is stored energy, it is a type of potential energy, which is energy stored in objects due to their location. An easy example of potential energy would be that of a bike on top of a hill where the bike's position is elevated and has the ability to roll down the hill. In the case of chemicals, the position refers to the various atoms that exist together within the chemical.
Application of Chemical Energy
Now that we understand that chemicals contain potential energy, let's explore the significance of chemical energy. In other words, what does chemical energy do for nature?
Let's play a word association game. What do you think of when I say 'The Circle of Life'? If you're like me, you probably thought of the Disney movie 'The Lion King'. Man that was a great movie! Another way of thinking about the circle of life is in terms of energy utilization within nature. Let me explain. Plants use energy from the sun to make sugar and oxygen from carbon dioxide and water. We, along with other animals, digest that sugar to release energy, so we can do work. Sugar is digested; in other words it's broken down, into carbon dioxide and water, which, in turn, is used by plants to make more sugar.
Are you getting the circle of life?
Chemical Energy in Everyday Life
We just talked about the fact that plants use solar energy to make sugar from carbon dioxide and water. Sugar, carbon dioxide and water are all chemicals that are held together by what we call chemical bonds or forces that hold the chemicals together. For example, all sugars are composed of carbon, oxygen and hydrogen atoms that are held together by chemical bonds. These atoms don't just stick together automatically. Rather, energy is needed to hold them together. Plants utilize solar energy to put the carbon, the hydrogen and the oxygen atoms together in the form of sugar. This is a really good example of energy transformation where energy is changed from one form to another. In this case, solar energy is converted into chemical energy that holds the sugar together and prevents it from falling apart.
We previously established that chemical energy is a type of potential energy where the energy is stored in the chemical bonds that hold the chemical together. Likewise, the potential energy can be released when the chemical bonds are broken. This is what happens when we digest the sugar that we eat. The chemical bonds in sugar are broken as the sugar is digested to carbon dioxide and water. When the chemical bonds are broken, the potential energy is released in the form of kinetic energy or energy of motion and heat or non useable energy. The kinetic energy is used to do work, such as contract our muscles and produce heat that helps to keep our bodies warm.
How neat is that? That's pretty neat!
Endothermic and Exothermic Reactions
We just finished talking about sugar as an example of chemical energy. Well obviously, sugar is not the only chemical that contains chemical energy. In fact, all chemicals contain energy. When chemicals are broken down, we refer to it as an exothermic reaction as energy is released from the reaction and can be used to do work. When a larger chemical is made from smaller building blocks, we call this an endothermic reaction as energy is required to build the bigger molecule from the smaller components. Gasoline is a large chemical we use to make our cars move. The engine breaks down the gasoline. As the chemical bonds holding the gasoline together are broken, the energy is released and used to move the car and generate heat. That's why my cats love to crawl under the hood of my car in the winter. They're not stupid. They know where the heat comes from.
In review, chemical energy is energy stored in chemicals'. Energy is 'the ability to do work. Chemical energy is a type of potential energy that is energy due to the position of an object or objects. The potential energy is in the form of chemical bonds that are forces that hold the atoms together in a chemical. All energy in nature ultimately comes from the sun, and chemical energy is no exception. Plants have the ability to convert solar energy into chemical energy. Specifically, plants put carbon dioxide and water together to form sugar. The formation of sugar from carbon dioxide and water is an example of an endothermic reaction as energy is needed to build the chemical. We, along with other animals, digest the sugar which releases energy that can be used to do work and generate heat. The digestion of sugar is an example of exothermic reaction as energy is release. All chemicals contain chemical energy and thus have the ability to do work.
Chapters in Science 101: Intro to Natural Sciences
- 1. Atomic Structure (10 lessons)
- 2. Properties of Matter (10 lessons)
- 3. Fundamentals of Thermodynamics (13 lessons)
- 4. Mechanics (7 lessons)
- 5. Relativity (6 lessons)
- 6. Electricity (11 lessons)
- 7. Magnetism (6 lessons)
- 8. Waves, Sound, and Light (18 lessons)
- 9. The Universe (18 lessons)
- 10. Atmospheric Science (6 lessons)
- 11. Geology (9 lessons)
- 12. Biomolecules (9 lessons)
- 13. Biology of the Cell (15 lessons)
- 14. Biochemistry Foundations (13 lessons)
- 15. Chemical Nature of the Gene (12 lessons)
- 16. Cell Processes (12 lessons)
- 17. Introduction to Plant Biology (16 lessons)
- 18. Human Anatomy (36 lessons)
- 19. Animal Reproduction, Growth and Development (8 lessons)
- 20. Genetics (10 lessons)
- 21. Ecology (11 lessons)
- 22. Evolution: Theories and Principles (8 lessons)
- 23. The Origin and History of Life On Earth (4 lessons)
- 24. Phylogeny and the Classification of Organisms (7 lessons)
- 25. Human and Social Biology (6 lessons)
People are saying…
"This just saved me about $2,000 and 1 year of my life." — Student
"I learned in 20 minutes what it took 3 months to learn in class." — Student