Another way to put it: Is evaporation possible when only one substance is involved?
Consider a closed vessel with water in gas and liquid state, in equilibrium. At the interface, the same amount of molecules migrate from liquid to gas and the inverse (dynamic equilibrium). Now, if we remove X molecules from the gas phase, molecules from the liquid phase will pass to the gas phase until equilibrium is achieved again.
What is the process describing this phase transition of the liquid molecules to gas: evaporation or boiling?
These are two types of vaporization. The definition from wikipedia (en.wikipedia.org/wiki/Vaporization) are rephrased below in order to mark their difference.
Evaporation (surface) occurs when the equilibrium vapor pressure is higher than the partial pressure of vapor of the substance.
Boiling (volume) occurs when the equilibrium vapor pressure is higher than the pressure of the "environmental pressure" (which I intepret as the total pressure surrounding gas).
I understand that in a single substance, the two cases are the same. Is this correct?
In other words, how would it be possible to achieve only evaporation in the single substance case. If by removing the X gas molecules will result in a pressure decrease. This suits best at the boiling definition.