Critical Point
The endpoint of a phase equilibrium curve in a P-T phase diagram where coexisting liquid and vapor phases become indistinguishable.
Governing formula
(∂P/∂V)_T = 0, (∂²P/∂V²)_T = 0
SI unit
Pa, K
In depth
Above critical temperature $T_c$ and critical pressure $P_c$, the distinction between liquid and gas disappears, forming a single supercritical fluid phase.
Examples in the real world
Supercritical Carbon Dioxide ($T_c = 31.1^°C, P_c = 73.9 atm$) used for decaffeinating coffee beans.