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HOW TO – Transform hand warmers in to liquid ice sculptures

Icy 485

Popular Science shows you how to make cool ice sculptures from the liquid inside hand warmers… –

The mechanism behind this is supersaturation. Hot water dissolves much more sodium acetate than does room-temperature water. Keep adding sodium acetate to a pot of nearly boiling water until it stops dissolving, and you’ve saturated the water. Let the pot cool and it stays liquid, even though now it’s holding far more sodium acetate than it should at the lower temperature: It’s now supersaturated.

The excess sodium acetate should precipitate out as the water cools, turning back into solid crystals. But it won’t do so without a trigger. In most hand warmers, that comes from a small piece of metal inside, but even a mote of dust could set it off. Once the process starts, it doesn’t stop until it’s all solid. The substance is not really freezing–in fact, the rapid precipitation releases heat, hence the hand-warming.

HOW TO – Transform hand warmers in to liquid ice sculptures – Link.

4 thoughts on “HOW TO – Transform hand warmers in to liquid ice sculptures

  1. Make it yourself. Sodium acetate is the salt thats formed when you mix baking soda and vinegar. I found 2 gallons of 5% white distilled vinegar for 3.50 at the local bulk shopping club. This requires about 512 grams(a 16 oz box and a couple extra table spoons) of baking soda. Mix it all together in a big pot (lots of foaming and bubbling) and boil it down to about 1/2 gallon. Making it this way it will have a slightly brown color. Let it cool. If it crystallizes when you cool it add a little distilled water, reheat and let it cool again. To trigger the reaction create some seed crystals by scooping a little out in a spoon and heating over a candle or other small heat source. You should get a white powder and thats your seed crystals. Scrape a little off into the liquid and it should rapidly solidify. You can also put the seed crystals into a dish and pour the liquid onto them building a sculpture.

  2. Be Careful! The precipitate will be VERY HOT and STICK to your skin. I had one of these liquid re-usable heat packs burst once and found out the hard way.

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