How can ice freeze in temperatures above freezing? By making instant hot ice, of course. Impossible? Possible! You can make this substance, which looks like ice but releases heat, with materials you can find in a store or at home by following the instructions below.
Steps
Method 1 of 2: with Store-bought Sodium Acetate
Step 1. Get Sodium Acetate Trihydrate
Although it is an inexpensive non-toxic ingredient, it is not easy to find in stores and it will be easier to buy it online.
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If you prefer to make this substance yourself, skip to the section Homemade Sodium Acetate Method. Note that homemade sodium acetate will make slower, duller hot ice - and in some cases it won't make hot ice at all if not prepared properly.
Make Hot Ice Step 1Bullet1
Step 2. Dissolve the sodium acetate trihydrate crystals
Dissolve as much sodium acetate as you can in hot, almost boiling water.
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Take the sodium acetate with a spoon and put it in the pot. The vinegar shown in this image is in gel form, because it was recovered from a thermal pad, but in most cases you will find it in powder form. Start with a cup of sodium acetate. Make sure you don't put it all in the pot, so you can use some of it as a seed for the crystals later.
Make Hot Ice Step 2Bullet1 -
Add water to the pot. Use the amount needed to dissolve the sodium acetate. The key is to saturate it with sodium acetate, so don't add too much water. The less water you add, the denser the solution will be, and the better the crystals will be.
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Heat the solution almost to a boil.
Make Hot Ice Step 2Bullet3 - Stir the solution continuously. This will dissolve the crystals. All the powder should dissolve and dissolve with the water until no more acetate can be dissolved. In other words, you should notice some undissolved powder at the bottom of the pot. (If not present, continue adding powder until the solution is saturated). Remember, it is important that the solution is at the highest possible concentration of sodium acetate. It is very important to continue mixing at this point in the process.
Step 3. When you have dissolved the acetate, pour the solution into a beaker of any size
Make sure the undissolved acetate stays in the pot. Do not pour undissolved powder into the glass.
Step 4. Chill the glass with the solution in the refrigerator for an hour or thirty minutes
At this stage of the process you are bringing the temperature below that at which the solution is saturated. Normally the dissolved crystals crystallize again after being cooled, but in this case, since the sodium acetate is in a supersaturated solution, it can "supercool", reaching a temperature below that of normal crystallization without crystallizing.
Step 5. Pour the solution into a container
Be careful not to spill it, and make sure the solution does not come into contact with solid sodium acetate. This step is optional, but if you want to put the solution in a container that allows you to better appreciate the ice formation, this is your chance.
Step 6. Tap the solid sodium acetate solution on a toothpick
The solution should become solid as soon as you touch it. By introducing a crystal "seed", you have just created a nucleation center, triggering the solidification process.
Step 7. Put your hands close to the outside of the container
It should radiate heat (the solid will be at 54 ° C) because the formation of the crystals releases energy. It is for this reason that sodium acetate is used in thermal pads and hand warmers.
Method 2 of 2: with Homemade Sodium Acetate
Step 1. Put 6 tablespoons of baking soda in a saucepan
Step 2. Add two liters of wine vinegar to the baking soda until it stops foaming
Add it a little at a time to avoid splashing, and mix often. When the solution stops foaming, the reaction is complete, and you will have a dilute sodium acetate solution. The solution should be transparent.
Step 3. Boil the solution until 90% of the water has evaporated (this may take some time)
The solution will be ready when a solid coating begins to form on top of it. You will have made a more concentrated sodium acetate solution (The solution will have turned slightly yellow or brown in color).
- When the solution boils, you will notice sodium acetate crystals adhering to the inside of the pot. Do not mix them in the solution; you will need them later, so scoop them up with a spoon and store them separately.
- Do not allow the film on the surface of the solution to become thick or complete; this indicates that another reaction is taking place which would ruin the "hot ice" effect.
Step 4. Move the reduced solution to a smaller container (preferably glass) and add 1 or 2 tablespoons of vinegar
The vinegar will help the solution stay liquid.
Step 5. Mix the solution
Make sure all solid particles are dissolved.
Step 6. Cool the solution in an ice bath
If an ice bath isn't a practical solution, you can put the container in the fridge; however, it will take longer to cool it down. When the solution has cooled, it will be "supercooled"; that is, it will be at a temperature below freezing without having assumed a solid form. You are now ready to make hot ice.
Step 7. Add some crystallized sodium acetate to your liquid solution
Use the powder residue you removed from the pot while boiling the solution. Start with a pinch or two; if you don't notice any effect, add more.
Step 8. Watch for hot ice to form
When you add solid sodium acetate to supercooled sodium acetate, a chain reaction will develop, causing the entire solution to solidify.
If that doesn't happen, there is a problem with your solution. Try again or switch to the store-bought sodium acetate method
Step 9. Put your hands near the container
It should radiate heat (the solid will be at 54 ° C) because the formation of the crystals releases energy. It is for this reason that sodium acetate is used in thermal pads and hand warmers.
Advice
- You can make ice sculptures if you pour the solution over a pinch of solid crystals. The solution will solidify upon contact with the crystals, and will continue to do so as you pour it. The ice will soon form a tower!
- Homemade hot ice won't be as functional as store-bought sodium acetate trihydrate.
Warnings
- Do not touch the solution until it has cooled down!
- Be careful not to inhale the solution. Even though it is a non-toxic substance, it is never a good idea to inhale chemicals.
