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Querulous One
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- TL;DR Summary
- Party balloons filled with Freon 12 go flat in a few hours, while helium takes two days. How can those larger molecules manage that (and they aren't even bosons)?
Years ago, I filled some latex party balloons with Freon 12. I haven't repeated the experiment with the Freon 134 that is available nowadays. It was fun to throw them around because Freon is so much heavier than air--you can throw them across the room and they land on the floor and stay there.
The first one went flat in about two hours. I of course assumed that the balloon had a very tiny leak or that I had tied the knot incorrectly, so I made a few more, along with some filled with air as experimental controls. The air-filled ones lasted days, as expected, but the Freon-filled ones again went nearly flat in two hours.
I know that chlorinated and fluorinated molecules have very unreactive surfaces, so you expect them to not be easily adsorbed onto solid surfaces, thus blocking nanopores. But helium is even less reactive--it can penetrate steel--and the single atom is certainly smaller than the Freon molecule. How does the Freon manage to escape so quickly?
The first one went flat in about two hours. I of course assumed that the balloon had a very tiny leak or that I had tied the knot incorrectly, so I made a few more, along with some filled with air as experimental controls. The air-filled ones lasted days, as expected, but the Freon-filled ones again went nearly flat in two hours.
I know that chlorinated and fluorinated molecules have very unreactive surfaces, so you expect them to not be easily adsorbed onto solid surfaces, thus blocking nanopores. But helium is even less reactive--it can penetrate steel--and the single atom is certainly smaller than the Freon molecule. How does the Freon manage to escape so quickly?
