Air Balloon On Liquid Nitrogen

Purpose

To demonstrate dramatically that the volume of vapor is greater than the volume of the same amount of liquid.
 

Equipment

Air balloon with styrofoam bucket of liquid nitrogen.

 

Images

i4-17

Description

An air balloon is held on top of a liquid nitrogen bath. The volume of the air balloon decreases for two reasons: first, the volume of the gas shrinks according to Charles' law, and second, some of the air changes to liquid and shrinks considerably. Liquid nitrogen will readily cause oxygen to liquify, and even liquify some of the nitrogen in the balloon.