All the processes discussed on the preceding pages (vaporization, sublimation, and fusion) occur during a heat addition to a substance. If heat is removed from a substance, the opposite of the described processes will occur.As previously described, a heat addition at a constant pressure to a saturated liquid will cause the liquid to evaporate (change phase from liquid to vapor). If heat is removed at a constant pressure from a saturated vapor, condensation will occur and the vapor will change phase to liquid. So the processes of vaporization and condensation are the exact opposite of each other. Similarly, freezing is the opposite process of melting and fusion. Sublimation also has an opposite process in which a gas goes directly to solid, but this process is not normally referred to with a unique term.

 

 

 

 

 

Reference:

DOE-HDBK-1012/1-92 JUNE 1992, THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW