Did you know that it is possible to freeze a liquid at room temperature? When you freeze it, it even gets hot! How can that be?
With the help of a parent or adult, you can try this for yourself. The first thing we did was get a type of salt called Sodium Acetate. We got this from Amazon.
The first thing we needed to do was find a sturdy dish. We recommend something heat resistant and also strong… Metal works best, though we used glass (though it ended up cracking, which you’ll see). When you find a metal dish, place it over the stove (turned off) and begin spooning in the sodium acetate. Put about 3-4 tablespoons full into the dish and mix with about 1 tablespoon of water.
Now, turn on the burner to begin heating the dish up! We turned the burner on to about 7 on the scale of 10. You can see some of the Sodium Acetate melting!
Once the substance in the dish is completely melted, put it into the fridge. Come back once the Sodium Acetate has cooled. Take a single solid crystal of Sodium Acetate, and place it in the liquid and watch! Notice any temperature changes!
Why is this happening? The best way to explain it is through the concept of Supercooling. Suppose you got a glass of distilled water that was very smooth and didn’t have any points for the water to crystalize on. You could theoretically cool the glass below freezing and the water would stay liquid. If you tap the glass the temperature of the water will jump up to 32 degrees F (0 degrees C), and the water will solidify quickly.
Sodium Acetate is like water, but its freezing point is at 130 degrees F. It is also more stable than water, and can be supercooled and remain a liquid. However, when you placed a piece of Sodium Acetate crystal in the liquid, that caused the freezing and the sudden jump in temperature.
What could you use this for? Well, it is already being used in hand warmers. Where else could you use the heat? Leave a comment and let us know!