Triple point of carbon dioxide
Channel: chewy
Date: 2015-02-09

The triple point of a compound is the point at which that compound exists simultaneously as a solid, liquid and a vapor. As a  student, it always seemed theoretical and "unreal" ... when in fact all those equilibrium lines are very relevant for a number of very real applications. This is a good way to show students solid carbon dioxide (dry ice) going to the triple point (solid-liquid-gas) and then return to a nice powdery solid once the pressure is released as the bulb pipette bursts. 

Is all this stuff about phase changes, equilibrium, and triple point relevant? oh yes!!