Q&A for How to Make Hot Ice

The first conclusion you can draw is sodium acetate exists in a supercooled liquid form below its usual freezing point. This is why the solution is capable of cooling to room temperature without forming crystals. The second conclusion is supersaturated solutions release heat upon crystallization (exothermic bond formation), which is why the "ice" feels hot.

Theoretically, yes. Apple cider vinegar contains a similar amount of acetic acid to white vinegar since they are both produced through the same process. However, apple cider vinegar is often distributed unfiltered/unpasteurized and will contain more impurities than white vinegar. These impurities may cause the ice to become solid sodium acetate sooner than you would want it to. Also, apple cider vinegar has a brownish color, which may not be the best choice when making hot ice.

Sodium acetate (CH3COONa) has a variety of uses. It can be used to neutralize sulfuric acid or create a buffer solution. CH3COONa is also sometimes used in heating pads and hand warmers.

Go with baking soda. Baking powder has a different acid level than baking soda and wouldn't work if you tried to use it.

No, it is not. The reaction would cause severe stomach problems including pain, nausea, and others. If you do ingest it, drink lots of water to dilute the solution.

You can dispose of hot ice safely by simply washing out the container and dumping it down the drain.

It could be a number of things. You may have either disturbed the solution or not have completely melted your sodium acetate, for example.

In this case, it's mainly just a fun experiment that you can do with kids.

No. Sodium acetate is a safe mixture. I don't suggest consuming it (it tastes terrible), but otherwise, just make sure the things you used to make it are clean for the next time you want to use them.

Theoretically, although it would be very expensive. Hot ice is solid at room temperature so it will not melt under normal indoor or outdoor conditions.

Clean is not a degree or percentage. It is either clean or it is not. If you have glassware that needs cleaning, look at some chemical options. Many exothermic methods can be safely done outside.

Yes, you can, as long as it doesn't become contaminated by other substances, you should be able to melt and refreeze hot ice over and over again.

Hot ice is just a fun experiment and has no practical use. Sodium acetate can be used to neutralize sulfuric acid, is used in hand warmers and used to give a salt and vinegar flavor to chips.

No, you cannot.

Hot ice generates heat when freezing, so it will not keep cool drinks cold. Also, while not toxic, hot ice tastes terrible.

Yes. The baking soda and vinegar make the crystals that are needed to make the ice itself.

The reaction that takes place is exothermic. Even though it is ice, it is hot, making it an exothermic reaction instead of an endothermic reaction.

No, you can't. Cooling for too long could cause the hot ice to freeze. Also, putting the hot ice in a refrigerator can ruin the sodium acetate.

Yes, you can keep it as long as it takes to cool down to room temperature. But make sure that it is in a sealed container, and to speed things up, you can put it in the fridge.

Set it out on the counter for approximately 2 hours (cover it). I haven't had success with putting it in an ice bath.

160 g of crystals add 30ml of water microwave it for about 1-2 minutes (until it boils). Let it sit for 2 hours. I make instant stalactites for my students with it.

This is because it carries heat too well and when the crust begins to form it would continue heating the mix and ruin it.