Constant Pressure: Balloons in Liquid Nitrogen

PIRA Class: 4E10.20

Purpose: 

Observe the change in volume of a container as the temperature of the gas within that container decreases.

Description:
Blow up the balloons and place them in the liquid nitrogen. They will contract to a very small volume and expand back to their original size once they warm back up.

Pour liquid nitrogen over an inflated balloon and observe balloon's volume to shrink, let it warm back up to room temperature.

Cautions: Always use eye and hand protection!

1. Arrange for obtaining Liquid N2 the day prior to the demonstration.

2. Place an inflated and tied off medium sized balloon into a large basin.

4. Pour LN2 over the balloon & stir the balloon about. (Stirring allow for a quicker result)

Note: Do not use too much LN2 - the purpose of this demo is to observe volume's dependence on temperature, not to observe a phase change.

5. Use tongs to pick up the deflated balloon and observe the balloon reinflate as it warms up to room temp.

Equipment:
Balloons, Liquid Nitrogen, large beaker, goggles, tongs, basin

Web Simulation:

https://www.youtube.com/watch?v=l5rYqexAyA0 

Location:
Shelf 164 (balloon), 262 (beaker), 264 (tongs), liquid nitrogen near the sink