Decomposition Reaction: Definition & Examples

An error occurred trying to load this video.

Try refreshing the page, or contact customer support.

Coming up next: Weak Acids, Weak Bases, and Buffers

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

Take Quiz Watch Next Lesson
Your next lesson will play in 10 seconds
  • 0:01 Decomposition Reaction Defined
  • 0:35 Examples of…
  • 1:49 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

Speed Speed Audio mode

Recommended Lessons and Courses for You

Lesson Transcript
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.

Expert Contributor
Christianlly Cena

Christianlly has taught college physics and facilitated laboratory courses. He has a master's degree in Physics and is pursuing his doctorate study.

Chemical reactions are classified into several different categories. In this lesson, you will learn about decomposition reactions so you can describe and identify them in the future.

Decomposition Reaction Defined

A chemical reaction is a process by which the atoms of one or more substances are rearranged to form different substances. There are many types of chemical reactions. These reactions are often classified by what they form or what happens during the course of the reaction.

A decomposition reaction is a type of chemical reaction in which a single compound breaks down into two or more elements or new compounds. These reactions often involve an energy source such as heat, light, or electricity that breaks apart the bonds of compounds.

Decomposition Reaction
Decomp React

Examples of Decomposition Reactions

A simple way to visualize a decomposition reaction is to use generic terms. Let's pretend we have discovered an elusive compound with the chemical formula 'AZ.' This means the compound is composed of an imaginary element 'A' bonded to imaginary element 'Z.' If we have a reaction equation that says 'AZ' yields 'A' + 'Z,' it shows a decomposition reaction. This decomposition reaction example breaks one compound down into two elements.

Decomposition reactions can also involve large compounds being broken down into smaller compounds, rather than being broken down into single elements. For example, the compound ammonium nitrate readily decomposes into dinitrogen monoxide and water.

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

Additional Activities

Decomposition Reaction Writing Prompts

Read each scenario below and provide a brief written answer to each question. Use the given lesson as a reference.

Prompt 1

Fractional distillation is the process of taking a chemical mixture and using heat to individually extract its components. This separation technique makes use of the varied boiling point of each chemical component. As an example, one can apply fractional distillation to an alkane solution containing water (boils at 100 degrees Celsius), pentane (boils at 36 degrees Celsius), and hexane (boiling point of 68 degrees Celsius). By heating up the sample, the component with the lowest boiling point would be collected first. For this solution, the first liquid to be collected would be pentane followed by hexane and water.

  1. In this scenario, is boiling a chemical reaction? (Refer to the definition of chemical reaction provided in the lesson)
  2. Would the given example be considered as a decomposition reaction? Why or why not?

Prompt 2

When calcium carbonate is subjected to heat, it divides into calcium oxide and carbon dioxide. This chemical reaction breaks down chemical bonds and separates the constituent elements. Calcium oxide or quick lime is an important end product of this process and is essential in glass and porcelain industries.

  1. Can the breakdown of calcium carbonate into components be called a decomposition reaction?
  2. What is the catalyst for this process to occur?

Answers to Prompts

Prompt 1

  1. Boiling of the alkane solution is not a chemical reaction. It induces physical change turning the liquid components into vapor.
  2. No chemical reaction occurs within the fractional distillation of the alkane solution. Hence, it is not a decomposition reaction.

Prompt 2

  1. In this scenario, calcium carbonate decomposes into components via a chemical reaction. Hence, it is a decomposition reaction.
  2. Heat is the catalyst of this decomposition and is required to break down the chemical bonds.

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
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? 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