How To Make Instant Hot Ice

by John P.

Hot Liquid IceWow, this video is incredible. Perhaps we’ve got some chemist in the OMB readership who will care to explain exactly how the heck this works!

This video demonstrates how to make a liquid that turns to ice at the touch of a finger. Must be one of the strangest reactions I’ve ever seen.

It looks like the only real ingredient needed other than water is Sodium Acetate.


{ 39 comments… read them below or add one }

1 Lisa Marie Mary November 3, 2007 at 9:19 am

Dude! That is so cool! I’d love to do that at home with my kids.

Why is it freezing in the metal pan, but, not the plastic one …until you touch it, that is? The kids would love the plastic one, so they could touch it and cause it to freeze.

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2 Brandon November 3, 2007 at 12:31 pm

Very cool :)

I’m going to give it a try too

I think they had touched the pans first to get some of the oil’s on it, that’s why it started to turn as they poured.

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3 Chris R. November 3, 2007 at 3:11 pm

It’s the same principle that is used to create rock candy- the sodium acetate has a much lower melting point than you’d expect (around 60 C), so when it is heated in the water, the solid you see turns to a liquid that ‘blends’ into the water.

On top of this, at a high temperature water can hold much more solute than at lower temperatures, but when you lower the temperature, that solute doesn’t just precipitate out right away, you get a supersaturated solution.

By touching it, he provided a nucleus for solid crystals to start forming, then after that it was just a self-sustaining reaction. I suspect that it froze on the metal pan and not when it was poured into the plastic because:

  1. it was being poured from a greater height, disturbing the solution more
  2. metal is probably a better nucleus for solidification than plastic.

If I got this wrong, chemists, please feel free to beat me with a large stick :)

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4 Derek Wong November 3, 2007 at 4:19 pm

Wow that IS cool!

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5 hthth November 4, 2007 at 9:15 am

Cool, it looks a bit like wax. I’ve always wondered what those multi-use bags contain that warm up when you bend them, now I know :)

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6 Marcia November 4, 2007 at 5:58 pm

Wow, that was totally awesome!! You sure conger up some cool stuff!!! I mean stories!

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7 Tom Barr November 4, 2007 at 6:17 pm

That’s what I would have said…..20 years ago when I took chemistry.

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8 MG November 5, 2007 at 12:21 pm

Yep, I read about this process a while back after seeing this video and a couple other “insta-freeze” ones somewhere. The whole instant crystallization process is awesome.. definitely makes for a fun chemistry experiment :)

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9 ............. November 7, 2007 at 3:30 pm

Coolio!!!!!!!!!!! Im a 5th grader and thats what i’m gonna do for my science project so i guess ill give it a shot

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10 Jeff November 9, 2007 at 12:52 am

Chemistry teacher here. I’ve done this demo in class for more years than I care to remember.

Chris R.’s explanation above is absolutely correct. Good on ya’ for paying attention in class! Sodium acetate supersaturates very easily because the acetate ion has a very “diffuse” charge when dissolved in water (it doesn’t have one particular “sticky” spot to strongly attract the positive sodium ion.)

You can make rock candy (large sugar crystals) the same way (but it doesn’t crystallize as quickly.) Dissolve as much sugar as possible in boiling water then let it cool slowly in a **clean glass** container. Then dangle a string in to provide a nucleation site.

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11 Jeff November 9, 2007 at 12:57 am

Forgot to mention: a very supersaturated solution might crystallize on the metal pans all by itself. But you could easily force this to happen by placing a small “seed” crystal on the pan and then pouring the solution on top of it. It would be guaranteed to start the crystallization process.

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12 Max November 11, 2007 at 11:03 am

Yea Sodium acetate Hot Ice is great you can buy it from ebay

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13 Brandy November 11, 2007 at 11:35 pm

Sooo…. this is really cool but make sure you do it right or it won’t work….. my friend tried doing it and it didn’t work because she didn’t sterre it all the time

HAVE FUN! TRY IT!

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14 josh B. November 13, 2007 at 8:15 pm

im in the 8th grade and i am doing this experiment for my science fair proj. Is there anything specific with like the water or anything? Can it just come from the sink or does it need to be soemhting different? and how long would i need to put it in the fridge to cool?

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15 ............. November 14, 2007 at 3:39 pm

You need distilled water and im doin it as a 5th grade science project

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16 Jeff November 14, 2007 at 7:11 pm

Chemistry Teacher here again.

Distilled or deionized water would be best but you can do it with any filtered or bottled water. The main idea is that there can’t be any “junk” floating around that could start the crystallization process before you want it to happen. Clean, well-scrubbed glassware is also a must for the same reason. Make a bunch of small samples because one or two may crystallize on their own no matter what.

I start by filling a few small test tubes with the NaH3CCHO then adding just a few drops of water to each (that’s all it takes). Heat them up in a hot water bath and stir each with a glass rod. When entirely dissolved, take them out and let cool to room temperature (NO FRIDGE NECESSARY!)

As long as no dirt gets in you can use the same samples over and over. Just reheat. Good Luck.

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17 Jeff November 14, 2007 at 7:29 pm

Whoops, that should have been NaH3CCO2. What was I thinking?

I also forgot to mention, sodium acetate is a hydrate (which means that the crystals already contain a fair amount of water). This is why you don’t need to add much water to get it to dissolve.

You can also make your own NaCH3COO (get used to different nomenclature!) It is the result of the well-known “kitchen” reaction of baking soda (sodium bicarbonate, NaHCO3) with vinegar (acetic acid, CH3COOH). You have to use distilled vinegar–no balsamic here! Use excess baking soda to react all the vinegar, filter out the unreacted baking soda, then boil the solution to drive off as much water as possible. Remember, you won’t see the crystals until it cools.

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18 josh B. November 14, 2007 at 7:37 pm

thanks, yall just helped me A LOT. I just havnt really been able to find specific directions to do this experiment.

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19 melissa January 29, 2008 at 9:36 pm

omg i have a project due with a partner and she wanted to this.. i couldnt find any info just videos the comments helped alot thnxx

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20 johnny February 9, 2008 at 12:28 am

This is not ice, it is sodium acetate turning solid…I wouldn’t put it in my drinks x_x

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21 ethan February 20, 2008 at 1:40 pm

I just fould out about this and it looks fun, but i can t find any sodium acetate. can some one tell me were too look other than Ebay.

when freezing it does it have to be at a sorten Temp befor i take it out??

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22 Amanda January 26, 2011 at 9:09 am

This is fun, I bought sodium acetate trihydrate at one of my pharmacy’s. Using sodium acetate trihydrate is the easiest way to make “Hot Ice”

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23 daniel balderrama March 13, 2008 at 6:04 pm

hello teacher i am from chihuahua mexico i want to know how many water do u use for the experiment and how many sodium acetate do u use.
and what temperature its when you start and what temperature do u put when u are stiring.
and how many time do u need fridge the water with the solution
because u try alot i cant make the ice can you help me pleace
my msn is danyboy_bt@hotmail.com thanks

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24 Jeff March 13, 2008 at 7:01 pm

Before you ask any more questions why don’t you read all the posts? I’ll bet your question has already been answered.

Temperature: It will work at room temperature or lower (but as it gets colder there’s a greater chance that it will spontaneously crystallize.)

Suppliers: As has been mentioned by previous posters you can find sodium acetate already pre-mixed in the right proportion with water (very little water, actually) as heat packs. It took about 5 seconds on Google to find these online suppliers (I Googled “heat pack”):

http://www.amazon.com/Instant-Reusable-Pack-Heating-Packs/dp/B000F3Q524
http://www.9thtee.com/reheater.htm

I’m trying to reason out how snapping the metal disc starts the crystallization. My current theory is that the shockwave aligns the acetate ions which starts the ball rolling. (Non-spherical particles suspended in a fluid will align during any shearing flow. This is sickeningly close to work I did for my Master’s thesis. Don’t ask.) Anyone else have any ideas?

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25 Jeff March 13, 2008 at 7:03 pm

Oops. Double post.

And read ALL the comments before you ask a question that has already been answered!

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26 Jen March 15, 2008 at 2:52 pm

I have tried this exp ALL Day and it’s not working. I have the sodium acetate and used tap water boiled a lot of the sodium into the water oured into a flask, cooled and poured into a dish…Nothing happened! Could you PLEASE help. I can;t find any exact directions.

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