Materials Required:
- Candle
- Match box
- 1 teaspoonful of baking soda
- Glass (not plastic) measuring cup,
marked for millilitres - Vinegar
Procedure:
- Set a candle on a safe place. Then ask one of your parents to light the wick.
- While the candle is burning, place the baking soda into the glass measuring cup. Look at the markings and notice where the 30ml line is drawn. Pour vinegar to this mark. The mixture will foam up for a few seconds.
- As soon as the bubbling has settled down a bit, slowly lift the measuring cup and hold the spout a few inches directly over the flame. Tilt the measuring cup forward as if you were going to pour out the contents, but do not let any solution dribble out. The flame will go out.
This is what happens:
Both baking soda and vinegar react to form carbon dioxide gas. This gas is invisible. It remained in the measuring cup until you tilted the spout forward. Then it flowed from the cup onto the flame because carbon dioxide is heavier than air. The flame was smothered with carbon dioxide and went out.
