相图 Phase Diagram Phase diagram Shows regions of pressure and temperature where phases are thermodynamically stable Vapour pressure Critical Pressure of a gas Solid Sublimation Vapour point in equilibrium with Liquid Pressure the liquid phase Pressure of gas in equilibrium with solid phase Triple point Vapour Phase Boundaries pressure, p Vapour separate regions and show p and T where T two phases exist in equilibrium Temperature, T Triple point Critical Temperature Vapour pressures increase with higher T, as the or solid Boltzmann distribution populates the higher energy states with increasing temperature相 图 Phase Diagram