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The chemistry of cold packs - John Pollard

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  • 9,369 Questions Answered
  • TEDEd Animation

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If you stick water in the freezer, it will take a few hours to freeze into ice. How is it, then, that cold packs go from room temperature to near freezing in mere seconds? John Pollard details the chemistry of the cold pack, shedding light on the concepts of energetics and entropy along the way.


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TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator John Pollard
  • Animator Henry Chung, Mark Storer, Noel Wong, Michael Field
  • Compositor Ricky Earl
  • Artist Ieuan Protheroe
  • Script Editor Alex Gendler
  • Narrator Addison Anderson
Additional Resources for you to Explore
Oil and water don’t mix based on energetics and entropy! Here is a link to a TED-Ed Lesson the educator wrote that discusses why.

Here is a link to a video from the educator's personal YouTube channel that provides a slightly more in-depth description of why substances mix or don’t mix based on energetics and entropy.

Do you know the difference between exothermic and endothermic reactions? Here is a great YouTube video that describes experimentally how to make a cold and heat pack, what exothermic and endothermic reactions are, and the science behind each.

For a list of endothermic versus exothermic reactions click this link!

Customize this lesson

Create and share a new lesson based on this one.

About TED-Ed Animations

TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator John Pollard
  • Animator Henry Chung, Mark Storer, Noel Wong, Michael Field
  • Compositor Ricky Earl
  • Artist Ieuan Protheroe
  • Script Editor Alex Gendler
  • Narrator Addison Anderson

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