Flame Out Science Experiment

Goal: Explain how a fire extinguisher works and emphasize its importance.
Ages: Appropriate for all ages with adult supervision.

Must be supervised.

Material List:

6 candles
Box of matches
Jug OR pitcher
Baking soda

What To Do:

1. Gather about a half dozen candles, a box of matches, a jug OR pitcher, vinegar, and baking soda.

2. Light the candles near, but at a safe distance from, the kids so they can see all of the flames.

3. Mix together equal parts of baking soda and vinegar in the pitcher and stir.

4. Pour out the CO2 produced by the mixture over the candles, making sure that none of the liquid comes out.

5. Explain that fire needs three things to burn: an ignition source, fuel, and oxygen. Then tell the kids how the mixture that was stirred together in the pitcher created carbon dioxide, which is heavier than oxygen in the air. Since the CO2 was heavier, it came out of the pitcher first and took away one of the elements that fire needs: oxygen.

6. Light the candles again, recreate the vinegar and baking soda mixture, and repeat the exercise.

Fire extinguisher icon

Note that a fire extinguisher works the same way; when the CO2 inside is sprayed on a fire, the flame goes out because it no longer has oxygen to use.

Bringing it All Together:

A fire needs an ignition source, fuel, and oxygen to burn. If you take one of those things away, the flame can’t feed on anything and will burn out. This exercise is to show what would happen if oxygen was taken out of the equation.

After explaining how a fire extinguisher works, make sure to emphasize that it’s important to have one or more of them around the house, garage, or farm. Encourage the students to go home and ask their parents to show them where the fire extinguishers are kept and how they work.