# Would evaporation still take place?

1. Dec 10, 2013

### willstaruss22

Ok so lets say Earths atmosphere is 300 Bar. Would water at 100 degrees F and at 300 Bar still have evaporation or would it just stay liquid?

2. Dec 10, 2013

### Staff: Mentor

Unless the gas above is saturated with vapor (100% humidity), water will always evaporate.

Actually it evaporates even when the humidity is 100%, just the condensation taking part at the same time counteracts drying out.

3. Dec 10, 2013

### willstaruss22

But how can it still have vapor with that much pressure? Im asking because I don't know if at 300x Earths atmosphere pressure water vapor would still exist or not.

4. Dec 11, 2013

### Staff: Mentor

No idea why you think pressure stops evaporation. It doesn't. It shifts the equilibrium, but it never stops the process.

That is, at very high pressures it may happen that we see only solids, and/or to see any non-solid phase we have to heat the substance above its critical point, at which moment gaseous phase is indistinguishable from the liquid and the discussion of evaporation becomes a moot. It can be easily read from the phase diagram. But as long as the gaseous phase exists, evaporation takes place.

5. Dec 11, 2013

### DrDu

With rising total pressure, vapour pressure even increases, so water would evaporate even more rapidly.

6. Dec 11, 2013

### mafagafo

You may be thinking that the equilibrium shift can reach a point where ONLY water solids would exist. That's somewhat intuitive but wrong. You can reach a point where one of the three phases is more abundant, but it's incorrect to assume that under any concrete conditions you would reach a state where only one phase of matter of water would exist.

7. Dec 14, 2013

### willstaruss22

That what im trying to ask because ive looked on a phase diagram of water and the states for water at 300 bar are solid, liquid or super critical liquid. So I was wondering if water was at say 80 degrees F if the evaporation would be in a different state because of the high pressure. that's all like I never see gas a on the chart with a pressure that high.