Would evaporation still take place?

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    Evaporation
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Discussion Overview

The discussion revolves around the behavior of water evaporation under extreme atmospheric pressure, specifically at 300 Bar. Participants explore the implications of high pressure on the phases of water and the conditions under which evaporation occurs, considering both theoretical and practical aspects.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants propose that water will always evaporate unless the gas above is saturated with vapor, even at high pressures.
  • Others argue that evaporation can still occur at 100% humidity, as condensation counteracts the drying process.
  • A participant questions whether water vapor can exist at 300 Bar pressure, expressing uncertainty about the phase behavior of water under such conditions.
  • One participant asserts that pressure does not stop evaporation but shifts the equilibrium, suggesting that high pressures may lead to only solid phases being present unless the temperature exceeds the critical point.
  • Another participant mentions that increasing total pressure raises vapor pressure, potentially leading to more rapid evaporation.
  • Some participants clarify that while equilibrium can favor one phase, it is incorrect to assume that only one phase will exist under specific conditions.
  • A participant expresses curiosity about the phase diagram of water, noting that at 300 Bar, the states are solid, liquid, or supercritical liquid, and questions how evaporation would behave at lower temperatures under such high pressure.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the effects of high pressure on evaporation and the existence of water vapor at 300 Bar. Multiple competing views remain regarding the relationship between pressure, temperature, and phase behavior of water.

Contextual Notes

Participants reference phase diagrams and the concept of critical points, indicating that the discussion is limited by the assumptions and definitions related to phase behavior under varying pressures and temperatures.

willstaruss22
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Ok so let's 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?
 
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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.
 
But how can it still have vapor with that much pressure? I am asking because I don't know if at 300x Earths atmosphere pressure water vapor would still exist or not.
 
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.
 
With rising total pressure, vapour pressure even increases, so water would evaporate even more rapidly.
 
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.
 
That what I am trying to ask because I've 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.
 

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