Chemistry / Unit 8 Chem 1438 short lesson, about 20 seconds
The Critical Point and the Supercritical Fluid
Captions available
The idea
A phase diagram's critical point is the temperature and pressure above which the liquid-gas boundary vanishes, forming a supercritical fluid.
In practice
Supercritical carbon dioxide removes caffeine from coffee beans as a solvent, leaving no chemical residue behind.
Where people slip
Above the critical temperature, no added pressure condenses a gas back into a distinct liquid — the two phases have merged.
Your place on the trail
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