- #1
SteveA001
- 13
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- TL;DR Summary
- Sealed bottle physics
If a bottle is partially filled with hot water and sealed, together what some air, what happens to the pressure inside the bottle as it cools to room temperature? Assumptions: The temperature of the air in the bottle will initially be about the hot water temperature as the bottle is first sealed, and the pressure inside will also equal the outside air pressure as the bottle is sealed. I notice my vacuum flask does not appear to build up a noticeable vacuum as I open it after my coffee has cooled, and the same lack of vacuum appears with a zip bag filled with water as it cools (no balloons handy unfortunately). So on the one hand experiment appears to indicate that a vacuum is not created, but on the other hand, would the pressure inside the bottle not be at water vapour pressure, which lowers as the temperature drops, and which starts at ambient pressure?