PX154 - C5 - phase diagrams

[YF 18.6]

3 phases separated by phase boundaries
at the triple point, where the phase boundaries meet, all three phases coexist
there is no liquid phase below the pressure of the triple point, and solid sublimes into the gas
- eg:
  - $C O_{2}$ "dry ice": $T_{t r} = 216.1 K; P_{t r} = 527 k P a \sim 5.2 a t m$
  - $H_{2} O : T_{t r} = 273.16 K; P_{t r} = 611 k P a$
there is always a phase boundary between solid and liquid at the highest pressure studied
gas liquid phase boundary ends at the critical point
no distinction between gas and liquid at temperatures/pressures above this