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How could a simple chemical
eaction put out a fire?
Watch this video to find out:
Here's how you can make one. Make sure you ask for help from
your parents and never leave candles
unattended.
What you need:
- Candles
- Matches
- Jug
- Vinegar
- Bicarbonate of soda
How to:
- Light the candles - ask a parent or guardian for help.
- Add several tablespoons of bicarbonate of soda to the jug.
- Pour white vinegar into the jug and mix.
- Tip the jug slightly and move it over the candles. Make sure
the liquid doesn't touch the candles.
Did you see the candles go out? How did it happen? You've
just made your own fire extinguisher.
How it works:
The vinegar and bicarbonate of soda react to form carbon
dioxide. This is heavier than air and so stays in the jug when the
jug is upright. When you tip the jug, the carbon dioxide pours
out.
Fire needs oxygen to burn. The air has around 20% oxygen. When
you tip the jug, the carbon dioxide pours out and pushes oxygen out
of the way. Without oxygen the candles go out.
Have a look at a red fire extinguisher. They work in the same
way as your fire extinguisher, by using carbon dioxide to displace
the oxygen that the fire needs to burn.