Contributed by David Jiang
Introduction
- We’ve all seen fire extinguishers before and its powerful stream of nitrogen which can smother a dangerous fire. However, imagine a fire extinguisher that can take out fires “invisibly”. Here is a fun experiment to design your very own, invisible fire extinguisher.
Materials
- 2 regular-sized cups
- Matches/Lighter
- 1 candle
- Vinegar
- Baking Soda
Procedure
- Put in a couple tablespoons of baking soda in a cup
- Pour a little bit of vinegar into the same cup and wait for the reaction to settle down
- Put a candle in another cup
- Use a match/lighter to light up a candle
- Use the cup and tilt it over the cup with the candle
- Make sure to not pour the liquid onto the candle
Physics Concepts and Questions
- Fire requires oxygen to burn
- The baking soda and vinegar makes a chemical reaction that makes carbon dioxide gas
- When you pour the carbon dioxide gas over the candle, it pushes the oxygen out of the the cup
- This is because carbon dioxide is heavier than oxygen, so CO2 sinks, and O2 rises
- There is no oxygen to fuel the candle anymore, so the fire goes out
Conclusions and Further Investigations
- Now that we have tested this experiment, it is time to look for other interesting ways to manipulate our extinguisher:
- Does the type of vinegar affect the performance of the extinguisher?
- Compare the time it takes for one type vs another
- What happens if you try to extinguish the candle when it’s not inside a cup?
- Does this make it harder/easier to extinguish? Or will it extinguish at all?
- Does the type of vinegar affect the performance of the extinguisher?
Citations
- https://www.stevespanglerscience.com/lab/experiments/co2-extinguisher/