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Candle Science Magic Trick

Blow Out a Candle Using Science


Blow out a candle by pouring a glass of what appears to be air onto the flame.

Blow out a candle by pouring a glass of what appears to be air onto the flame. This easy science trick demonstrates what happens when air is replaced with carbon dioxide.

Anne Helmenstine
You know you can put out a candle flame by pouring water on it. In this science magic trick or demonstration, the candle will go out when you pour 'air' onto it.

Candle Science Magic Trick Materials

  • a lit candle
  • a transparent glass (so people can see what is inside the glass)
  • baking soda (sodium bicarbonate)
  • vinegar (weak acetic acid)

Set up the Magic Trick

In the glass, mix together a little baking soda and vinegar.

How to Blow Out the Candle with Chemistry

Simply pour the gas from the glass onto the candle. The flame will be extinguished. Another way to perform this trick is to pour the gas that you just made into an empty glass and then pour the apparently empty glass over the candle flame.

How the Candle Trick Works

When you mix baking soda and vinegar together, you produce carbon dioxide. The carbon dioxide is heavier than air, so it will sit in the bottom of the glass. When you pour the gas from glass onto the candle, you are pouring out the carbon dioxide, which will sink and replace the (oxygen-containing) air surrounding the candle with carbon dioxide. This suffocates the flame and it goes out.

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