Instant Hot Floss - a Simple But Fascinating Experiment!!

In this experiment we will be able to observe the chemical reaction that occurs when vinegar and sodium bicarbonate are mixed. It is a surprising experiment because you will think that we are making ice when in fact we are playing with instantaneous crystallization. In this chemical reaction we will observe bubbles of carbon dioxide (gas) and another liquid product, sodium acetate, with which we can make hot ice although it is not really ice. We use the term hot because heat is produced in this crystallization process.

• 750 cl of white vinegar.
• 55 g of baking soda.
• A saucepan
• A spoon.
• A glass graduated in cl to measure the capacity of the vinegar.
• A scale to weigh bicarbonate.
• Glass container that resists heat.
• Foil.
• Home appliances:
• Fridge.
• Ceramic hob

We start by mixing 750 cl of white vinegar and 55 g of baking soda in a saucepan. For this we have used the scale, to be able to weigh the exact amount of bicarbonate. When mixing these substances, we observe that there is an effervescent reaction, bubbles. This is the gas that is released from the mixture, that is, carbon dioxide. That is why we had to gradually mix the bicarbonate, since a lot of foam came out and it could come out of the container, while we stirred slowly with a spoon to favor a more homogeneous mixture.

(you can also buy sodium acetate)

When the effervescent reaction ends we observe that there is no more foam, that is when we have achieved a homogeneous solution. Then we boil said liquid at medium temperature, that is, we put the hob on the minimum, to prevent it from boiling too quickly. Let it boil for approximately 1 hour (we want the water in the mixture to evaporate). The most difficult part of the experiment was being able to verify the exact moment to put out the fire, since we had to observe a very thin crust or film inside the mixture. We were watching practically all the time so that we didn't miss that moment. It is then when most of the water will have evaporated and in the saucepan we will have a very concentrated solution (with a lot of solute) of sodium acetate.

Then we took the glass vial and slowly passed through the sodium acetate. It had to be done very carefully, as it was very hot. We cover it with a piece of aluminum foil and put it in the freezer for about 1 hour. But during this time we observed how the liquid was acquiring a less liquid and more dense texture. We were able to see how some small crystals had formed in the bottom and on the sides of the saucepan.

After the time has elapsed, we remove the glass container from the freezer and uncover it.

It is then that we put an object inside the jar, in this case a spoon, and we observed that in seconds the liquid began to crystallize, until it did so completely. Was it really ice? Ice that was forming in a few seconds? What we have actually seen is a process of crystallization of sodium acetate, not ice, although its physical appearance does seem so. This occurs because this state in which the sodium acetate is found is unstable, therefore any small disturbance, such as introducing the spoon, causes crystallization to occur.

If we touch the container with our hands, we notice that it has warmed up a bit, since energy is released in the form of heat in this crystallization process.