Fill an empty 2 liter bottle 1/3 full with the hottest tap water you can get. Immediately screw the cap on. Set the bottle aside and let it cool. The side buckles. Why?© BrainMass Inc. brainmass.com March 4, 2021, 6:23 pm ad1c9bdddf
When you fill an empty 2 liter bottle 1/3 full the remaining 2/3 volume of the bottle is occupied by air. Since the water is hot the air also is hotter than the room temperature.
The gas law is PV = n R T
P = Pressure
n = no of moles
R = gas constant
T = Temperature
This can also be written as
PV/ T = n R
Since the air does not escape from the bottle as the cap is screwed on , the number of moles of ...
Explains why when an empty bottle is filled 1/3 full with hottest tap water one can get with, the cap is screwed on immediately and the bottle is set aside to let it cool, the side buckles.