Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: scientizscht on 29/05/2020 21:10:01
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Hello
Is it possible to have a sealed bottle partially filled with water and partially with void?
How will the water sit in the bottle? Just like the bottles with water and some air?
Thanks!
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By void you mean a vacuum?
I think the water will boil until the pressure has raised the boiling point to match the ambient temperature.
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Here's one way of doing it:
Now if you just used a non-compressible bottle instead of a compressible drum, you would end up with the bottle half-filled with water, and the remainder filled with a low-pressure water vapor.
By reducing the temperature, you can further reduce the pressure of the water vapor.
- You can work it out from the phase diagram of water:
- at a temperature of 0.1C 0.01C, you can have a container with liquid water and water vapor at a pressure around 0.6% of normal Earth atmospheric pressure (if I am reading this correctly...).
- This is called the "triple point of water", because water can coexist as a solid, a liquid and a gas; you can have ice floating in boiling water!
See: https://en.wikipedia.org/wiki/Phase_diagram#Crystals
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at a temperature of 0.1C, you can have a container with liquid water and water vapor at a pressure around 0.6% of normal Earth atmospheric pressure (if I am reading this correctly...).
Close...
It's 0.01C
And it's important because it's the defined point on the Kelvin temperature scale; 273.16K exactly.
But a bottle with just water vapour and water looks pretty much the same as one with water and (damp) air.
Things get interesting again at 373.946 °C, 217.75 atm
https://en.wikipedia.org/wiki/Critical_point_(thermodynamics) (https://en.wikipedia.org/wiki/Critical_point_(thermodynamics))