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How to make hot ice with sodium acetate? Answered

Using 100 gram bottles of sodium acetate and boiling into water to water can't handle any more crystals. Then I pour into a glass and cool off in fridge, then pouring into another container to try to get the "freezing" effect but nothing happens. Any ideas what i'm doing wrong? 



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9 years ago

I used to sell these Sodium-acetate bags in vinyl and plastic.
There is a stainless pop-clicker in the bag to start  the exothermic
After using the heater, it is recharged by boiling the bag fore a few
minutes to re-dissolve the crystals back to a clear liquid in a
see through bag.

Watch the video to see the rate of crystallization.
You see me messaging the bag to keep it pliable otherwise it gets
rock hard.

An Interesting Scuba-Diving Application :
You need to understand,  marine poisons as a group are destroyed
rendered ( non-toxic ) by high temperatures ( a result of the ocean temp ). 

That knowledge was very useful to me when I clumsily punctured my
thumb on the mildly poisonous barbed spine of a small reef shark's
dorsal fin.
The pain enough to make you loose context in conversation,  I was
told would take six plus hours to pass away. 

I did have several of the plastic ( hotter ) heat packs for wet suit warming.
And after a few more minutes of painful thumb agony,
I activating several of my heat packs and wrapped them around my thumb.
Keeping them wrapped around the thumb despite the very unpleasant
( Dam Hot ) burning sensation took some effort of will.

But 45 minutes later my now red thumb was free of any pain !!!



9 years ago

I did similar demonstrations in the lab a couple times. The main departure from your explanation is the use of water. You add crystals to boiling water whereas we pretty much just melted crystals with only the tiniest amount of water added.
You CAN use the boiling water to warm up the container with the sodium acetate indirectly (you only need to reach like 60ºC). At the time we used an electric heating pad. Avoid open flames.

Once it cools (is faster in a fridge but not necessary) you have a supercooled liquid (a substance that is still liquid even though it is below its freezing point). To get it to "freeze" it needs a nucleation point (something where the crystals can start to grow on). This can be a speck of dust, a stick or even a shockwave in the liquid from putting down the container too hard. If you plan on repeating the melt-freeze cycle I suggest you use another sodium acetate crystal for nucleation, like this you don't introduce impurities.

I hope it is not necessary to mention this but be careful... Boiling water is dangerous, solidifying supercooled liquids are very dangerous (by god, don't get any on your skin), and thermal shock can be dangerous in the container you are using to cool the acetate.

Lastly, Do check out the videos mentioned by frollard. They will answer anything I missed and correct anything I got wrong ;)


9 years ago

Check out the nurdrage videos on youtube - they specify EVERYTHING you need to know.