Boiling liquid nitrogen is used to blow up (in both senses!) a balloon!
WATCH VIDEO
Possible Incorporated Topics:
- Temperature and Pressure
- Phase Transitions
Theory:
Liquid nitrogen has an extremely low boiling point of approximately -196 〬C. This means that it boils at room temperature. When it boils, it becomes nitrogen gas which has more volume than when it was a liquid. When the liquid poured into a closed container, an increase in pressure will result as it boils into gas. When the pressure inside the container becomes higher than the pressure outside the container, the gas will try to push out on the container by the easiest means available (which may sometimes mean EXPLOSION).
In this demonstration we used a water bottle with a balloon on top. This was a closed container, but since the balloon has more elasticity than the bottle, it can clearly demonstrate the gas expansion. When the pressure builds up in the bottle/balloon, it pushes out on the balloon causing it to inflate. If there are no leaks in the balloon or the bottle, the pressure will inflate the balloon so much that it will pop.
Apparatus:
- Balloon
- Liquid nitrogen
- Empty pop or water bottle
Procedure:
- Start pouring liquid nitrogen into the water bottle. How much may depend on how big your balloon is, but generally you will only need to fill the bottle approximately 1/3 of the way up.
- When done pouring, attach your balloon over the mouth of the pop bottle. Make sure there are no leaks (if you want it to pop).
- Stand back and observe the balloon inflate with the nitrogen gas.
Safety:
Be very careful when using liquid nitrogen, wear safety goggles. Don't let it touch you or your clothes.
