4C50.10 Critical Opalescence

Set up the projector to display the shadow of the liquid CO2 on a screen. Turn on the heater and let it run until it hits the critical point, then switch to the cooling fan to let the CO2 separate. When shadow projecting use an inverting prism to keep the liquid on the right (down) side.

Heating ~15 sec
Cooling ~ 75 sec
T critical=31C=304 K
Pressure Critical 73 atm!

Can also be done very effectively with a camera and video projection as shown in photo below.