Microwave soap science experiment : Fizzics Education


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Microwave soap

Microwave soap

Follow FizzicsEd 150 Science Experiments:

You will need:

  • A microwave-safe bowl.
  • Household soap, wet soap works best. So use an old bar of soap from the shower.


Soap in the microwave science experiment - materials needed
1 Soap in the microwave science experiment - beginning the experiment

Place the bar of soap in a microwave-safe dish and zap it on high for between 30-60 seconds.

2 Soap in the microwave science experiment - soap after 35 seconds

You may need longer for low power microwaves.

3 Soap in the microwave science experiment - soap following 100 seconds

Watch as a foamy mass grows from the soap! (Careful; do not touch until the soap is cool).

5 Teacher showing how to do an experiment outside to a group of kids.

Online courses for teachers & parents

– Help students learn how science really works

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6 A man holding a blow torch onto a white tile whilst wearing safety glasses

Get the Unit of Work on Heat Energy here!

  • What actually is heat?
  • How does heat move through different materials?
  • How does heat change the properties of materials and more!

Includes cross-curricular teaching ideas, student quizzes, a sample marking rubric, scope & sequences & more

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Why Does This Happen?

The water inside the soap is undergoing a phase change from liquid to water vapour, and expanding. The foamy effect comes about from the expansion of the air bubbles trapped inside the soap. By heating the soap and expanding the water and air inside, you end up with this lovely warm soapy foam.

Variables to test

  • Try different types of soap
  • Vary the strength of the microwave setting

A man with a glove above a liquid nitrogen vapour cloud

Learn more!


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