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Easy⏱ time20 min$ cost4

CO₂ Candle Snuffer

Pour invisible carbon-dioxide gas over candles to put them out without touching them.

Start building ↓
fig — working model Result first

The build

Step 01

Light the candles

Set a row of small candles safely.

Step 02

Make the gas

React baking soda and vinegar in a jar.

Step 03

Let it settle

CO₂ collects in the jar, heavier than air.

Step 04

Pour it out

Tip the gas (not the liquid) over the flames — they go out.

Working Principle

The reaction makes carbon-dioxide gas, which is denser than air and doesn't burn, so pouring it over a flame starves it of oxygen.

The science behind it

A closer look

Fire needs oxygen; replacing the air around a flame with inert CO₂ smothers it — the basis of CO₂ fire extinguishers.

Take it further

Variables to test

  • 1 Snuff candles of different heights — which goes first?
  • 2 Why does the tallest candle survive longest?

More Chemistry