demonstrations:carbon_dioxide_extinguisher
Carbon Dioxide Fire Extinguisher
Materials: ★☆☆ Easy to get from supermarket or hardware store
Difficulty: ★☆☆ Can be easily done by most teenagers
Safety: ★☆☆ Minimal safety procedures required
Categories: Chemical Reactions, Combustion, Gases
Alternative titles: Fire Extinguisher, Vinegar and Baking Soda
Summary
Baking soda and vinegar react to produce carbon dioxide gas, which is then poured over lit candles to extinguish the flames. This models how fire extinguishers use gases to smother fire.
Procedure
- Place candles in a clear glass beaker or bowl.
- Light all the candles carefully.
- In a separate large beaker or bowl with a spout, add about 4 teaspoons of baking soda.
- Pour in approximately 1 cup of vinegar.
- Allow the reaction to proceed for about one minute, letting carbon dioxide gas accumulate above the liquid.
- Gently tilt and “pour” the invisible gas from the reaction container over the burning candles, without spilling the liquid.
- Observe the flames extinguish as the carbon dioxide displaces oxygen around the candles.
Links
Extinguish Fire with Carbon Dioxide experiment - Kids Fun Science:
📄 Fire vs. Fizz: Using carbon dioxide to extinguish a flame - Small Step For STEM: https://www.smallstepforstem.com/fire-fizz-carbon-dioxide/
Variations
- Use different sizes of containers to show how much gas is needed to put out the flames.
- Try extinguishing just a few candles first, then increase the number.
- Compare the effect of exhaling (carbon dioxide from breath) over a candle with the baking soda and vinegar reaction.
Safety Precautions
- Use caution with open flames—tie back long hair and secure loose clothing.
- Keep flammable substances away from the flames.
- Be careful with hot liquid wax, which can cause burns.
- Have an operational fire extinguisher in the classroom for emergencies.
Questions to Consider
- What evidence shows that a chemical reaction occurred between baking soda and vinegar?
- Why does carbon dioxide gas put out the flames?
- How is carbon dioxide different from air in terms of density?
- What are the reactants and products in this chemical reaction?
- How is this demonstration similar to how real fire extinguishers work?