My guess is that it’s not ice at all, but some sort of liquid that turns to a gel when poured. Does anyone have the straight dope?
This looks a lot like a super saturated solution of salt water poured onto a surface contaminated with salt crystals. As soon as the “super solution” encouters a propagation point, the dissolved ions start crystalizing in a dramatic display.
I have seen this demonstration in college General Chem class. It was similar to what I saw on the video.
I believe it is a super saturated solution of sodium acetate. It’s fun stuff to play with. It actually gets hot when it crystalizes.
Here it is
http://www.youtube.com/watch?v=uy6eKm8IRdI
It could be a supersaturated solution of almost anything. When I took Chem 1 in college (before these courses got labeled 101), we made a saturated solution of glucose in boiling water, put a thermometer in it and let it cool, undisturbed, to room temperature. One little disturbance and it solidified instantly. The temperature shot up from, say, 20, to 50 or 60 degrees C.
I think you can get a similar effect with supercooled water, but it might heat enough to prevent instant freezing.
Is it possible that it’s super cooled water like in the video below, or won’t super cooled water behave as it did in the video in the OP?
I’ve seen that video before on YouTube, and it was labelled as supercooled water. There were a few other videos which went with it, some of which included shots of thermometers. And I’ve seen similar effects myself, with what I know was nothing but water.
I seriously doubt it was just water. I’ve seen supercooled water in bottles before, and have rarely seen it in an uncapped flask. There was a discussion years ago here about if a beaker of water could actually be supercooled and caused to quickly freeze. I’ve seen it but I’m of the opinion it is too unstable to be jostled around in an uncapped container as in the video.
The supercooled solution of sodium acetate (trihydrate I believe), is much more stable, and behaves just like what is in the video. Since this is a relatively common chemistry education demonstration; I’m sure this is what it is.
Every time I opened a bottle of super cooled soda, it freezes from the top down before I can even take a drink. So I don’t see how that bottle could be filled with water.
I once did something close to the video accidently, with supercooled water.
It was unseasonably cold, so I was putting bottles of just boiled water in my dog’s house before leaving for work. One morning, I took yesterday’s bottle out, and as I poured it into the sink, something like in the video happened…I wasn’t trying to pour smoothly, so in addition to the pile of slush in the sink, the remaining contents of the bottle turned to slush about halfway empty. I had to forcably shake the bottle to get it empty.
Things I think were important:
-I’d been doing this several days straight, so the bottle had been flushed with boiling water numerous times, so was absolutely clean. (no dirt to form nucleation sites)
-The water was at a hard boil as I poured it into the bottle. (no air bubbles to form nucleation sites)
-The doghouse allowed the bottle to chill very slowly over the course of 24 hours or so, and the deep chill came only as the air cooled overnight.
-The overnight low temperature was around -5F. I have no idea how cold the water got, but it was certainly well below 32F.
I’ve looked at it again.
I’m not so sure it isn’t just water that has been cooled to -6. It seems more watery than a sodium acetate solution and appears to melt a bit as time goes on.
An unopened bottle of diet Pepsi placed in the freezer for a hour will freeze in a similar manner when you pour the contents into a glass.