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CH1012
OTHER TRANSITIONS
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b) Solid           Vapour
       Sublimation
ln p = -DHsub/RT + constant
  Multiple stable phases may exist
  for the  same physical state eg. Ice I, Ice II ...
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c) Solid           Liquid
Melting point varies slightly with pressure
eg. water mp. = 0.0000oC     at 760 torr
= 0.0098oC at 4.58 torr
- solids & liquids are nearly incompressable
P
CO2
1 atm pressure
1) CO2(s) sublimes at -78oC
P
CO2
P
H2O
P
H2O
 [ Ice melts at 0oC ]
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