Exothermic Reaction: Definition & Example

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Lewis Acid: Definition, Theory & Examples

You're on a roll. Keep up the good work!

Take Quiz Watch Next Lesson
 Replay
Your next lesson will play in 10 seconds
  • 0:00 What is an Exothermic…
  • 1:28 Examples of Exothermic…
  • 2:49 Lesson Summary
Save Save Save

Want to watch this again later?

Log in or sign up to add this lesson to a Custom Course.

Log in or Sign up

Timeline
Autoplay
Autoplay
Speed Speed

Recommended Lessons and Courses for You

Lesson Transcript
Instructor: Derrick Arrington

Derrick has taught biology and chemistry at both the high school and college level. He has a master's degree in science education.

Many chemical reactions occur everyday and can have very different results. In this lesson, you will learn about chemical reactions that are considered to be exothermic.

What Is an Exothermic Reaction?

We usually think of chemical reactions as happening in laboratories with lots of vials and different colored solutions being poured into each other. But have you ever built a campfire using a match to ignite the flame? The fire created by the match is a chemical reaction, too!

Any process that rearranges the atoms of one or more substances to become a new substance is known as a chemical reaction. Chemical reactions are routinely completed in labs and occur as natural processes in the environment. Many chemical reactions absorb or release heat and energy as part of the process.

An exothermic reaction is any reaction that releases or gives off energy during the reaction. You can remember this by putting together 'exo-' which means to exit, with 'therm' which refers to heat. So a reaction where heat or energy leaves or is released is an exo-therm-ic reaction. (The opposite of an exothermic reaction is an endothermic one, where endo- means to absorb or let in energy.)

The energy given off can be in multiple forms, including heat, light, sound, or electricity. This energy is normally obtained as a result of bonds being broken during the reaction. In a molecule or compound, a majority of the energy is held in the bonds that link the molecules. Bonds have varying strengths. When a reaction occurs that causes these bonds to break, it gives off energy and is, therefore, exothermic.

Examples of Exothermic Reactions

Exothermic reactions are very common. Let's take our match example from the beginning. The friction that is caused when you rake the match head against a rough surface ignites the phosphorus and potassium chlorate in the head of the match and they continue to burn with the oxygen in the air. This creates a flame, which is a definite sign that an exothermic reaction is taking place as heat and energy are being given off.

To unlock this lesson you must be a Study.com Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use Study.com

Become a Study.com member and start learning now.
Become a Member  Back
What teachers are saying about Study.com
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? Study.com has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account
Support