Quick Question About Plastic Bottle Delfating

[QuantamMan]

Hi Guys,

I am new here, but I have a quick question.
I had a somewhat tepid liquid in a plastic soda plastic 2L bottle
When I tightened the cap to close it all was well and normal
After a day a portion of the top of the bottle deflated, as if oxygen was sucked out

Can someone explain this process?

Thank You
QM

 

[omoplata]

Was the water warmer than room temperature?

If yes, the temperature of the bottle and the water became equal after you closed the cap. The air volume contracted as its temperature went down. It couldn't get air from outside because the cap was closed.

http://en.wikipedia.org/wiki/Thermal_expansion"

 

[QuantamMan]

Was the water warmer than room temperature?

yes, we have been having snowfall lately, it's cold right now

 

[omoplata]

Here is a clearer and more correct explanation.

Let's assume when you closed the cap, the bottle, the air inside it, and the soda were at the same temperature. When you closed the cap, matter (air) couldn't move in or out of the bottle, so you made it a http://en.wikipedia.org/wiki/Closed_system" . So air contracted more as the temperature reduced. That's why the soda volume seemed to be the same but the air volume appeared to be less.

You can look up these terms in your science textbooks too.

 

[pmacias]

Hello QM,

Thank you for your question. The process you are describing is known as "plastic bottle deflating" or "bottle collapse". This can occur when there is a difference in pressure between the inside and outside of the bottle, causing the bottle to shrink or collapse.

In your case, the tepid liquid inside the bottle may have warmed up and expanded, creating pressure inside the bottle. When you tightened the cap, you sealed the bottle and trapped the warm air inside. As the air cooled down, it contracted and created a lower pressure inside the bottle compared to the outside air pressure. This difference in pressure caused the bottle to deflate.

Another possible explanation is that the plastic used to make the bottle is not very rigid, and the weight of the liquid inside caused the bottle to shrink over time.

I hope this helps answer your question. If you have any further questions or concerns, please feel free to ask. Thank you for your interest in science!

Best,