I love reading this site and, up till now, have been able to answer most of my own questions by doing research on the Internet. But here’s one that I haven’t found.
What is the liquid that freezes inside a freezer mug? Some people have told me it was just water, while others have told me other things are added to the “water-like” solution to keep it from cracking the mug. Anyone actually know?
Spluuuman.
Well…it tastes like gasoline…owww…I don’t feel too good…
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thump
I have some of the “freezer mugs” that you’re talking about, and at the moment, some of them were in the freezer, and others were not. I’m assuming that they’re all identical, so it would be the same if I looked at one before and after putting it in the freezer. What I noticed is that the ones that were sitting out had a lot of empty space in the section where the liquid is, and the frozen ones (though I couldn’t tell for sure) seemed to be totally full of the stuff. This could indicate that the stuff is just water, because water crystallizes and expands when you freeze it. But it could be something else entirely. If you don’t have any of these, and you want me to do some informal experimentation on them, let me know. Welcome to the SDMB!
I do have some of those freezer mugs in my freezer now and I have seen the air in the mug. But that just brings up another question! If it IS really just water and it just fills up the empty portion of the mug with ice, where does the air that was in there before go to? I don’t see any holes for the air to escape to so the ice can fill up the remaining area. If it was air tight, the mug would crack from the pressure of the growing ice, right?
Spluuuman.
We have two Pilsner-type mugs from CVS, these are half-filled with some sort of gel.
If it IS really just water and it just fills up the empty portion of the mug with ice, where does the air that was in there before go to?
It doesn’t go anywhere. It just gets squished into the remaining space.
If it was air tight, the mug would crack from the pressure of the growing ice, right?
No, the point would be to give the ice room to form so it doesn’t apply pressure to the container. Now, the air is going to be pressurized when this happens, but air is compressible, where ice isn’t. The mug can easily withstand the air pressure that develops.