Dry Ice Flame Extinguisher

A lit candle inside a cup goes out when dry ice is added. As the dry ice sublimates into carbon dioxide gas, it displaces oxygen around the flame, showing that fire needs oxygen to burn.

1. Place a candle in a cup and light it.
2. Using a spoon or tongs, add a piece of dry ice into the cup near the candle.
3. Watch as the flame goes out once carbon dioxide replaces the oxygen.

Dry ice candle extinguisher - Sarah Thacker (produces carbon dioxide bubbles by mixing dry ice and warm water):

📄 Candle & Dry Ice Science Experiments - Preschool Powol Packets: https://preschoolpowolpackets.blogspot.com/2016/12/candle-dry-ice-experiments.html
📄🎞️ Carbon Dioxide Flame Extinguisher - Rutgers-New Brunswick Department of Chemistry and Chemical Biology: https://chem.rutgers.edu/cldf-demos/1026-cldf-demo-carbon-dioxide-flame-extinguisher

• Try different sizes or amounts of dry ice to see how quickly the flame goes out.
• Measure how full the cup gets with carbon dioxide by lowering a candle at different heights. An alternative could be to have a larger container with several candles at different heights.
• Produce carbon dioxide bubbles using warm water and dry ice, then pour it onto the flame.

• Always use adult supervision when working with fire and dry ice.
• Handle dry ice with thick gloves or tongs - never touch with bare skin.
• Do not place dry ice in the mouth or attempt to drink anything containing it.
• Perform in a ventilated space to avoid buildup of carbon dioxide gas.
• Be cautious with the open flame and keep flammable objects away.

• Why does carbon dioxide make the flame go out?
• How is this experiment similar to covering a candle with a glass?
• Why does carbon dioxide sink to the bottom of the cup instead of rising?
• How does this demonstration connect to real-life fire safety methods, such as using a CO₂ extinguisher?