Recently, I discovered a video that claimed it was possible to make a cooling pack that can absorb more heat than twice its weight in ice using mostly kitchen supplies, therefore I decided I must test it out.
In this video, NightHawkInLight claimed that making a saturated solution of sodium sulfate would produce a suspension of solid sodium sulfate crystals that will absorb large amounts of thermal energy to melt, resulting in a slurry that remains cool until all of the sodium sulfate has been melted.
Making Sodium Sulfate
To make this solution, I would have used some sodium sulfate that I purchased, but I didn’t have any, therefore, I was obligated to make some. I brainstormed to figure out how I could make sodium sulfate, at which point I suddenly realized that I could make it using only two household ingredients.
Utilizing one of my favorite chemical reactions — the double displacement reaction — I combined Epsom salt and washing soda, which slowly produced sodium sulfate in cold water, but it produced the sodium sulfate much more rapidly when the solution was heated. An amazing characteristic about this reaction is that the byproduct is magnesium carbonate, which can apparently be useful in pyrotechnics — I’ll be putting this to the test soon!
Here is the formula for the reaction that I performed.
MgSO4 • 7 H20 + Na2CO3 • 10 H20 -> MgCO3 • 3 H20 + Na2SO4 • 10 H20 + 4 H20
Making the Cooling Pack
Normally, you would start off with a stainless steel pot that is only used for chemistry purposes, but I didn’t have one, instead, I used an assortment of some crude and homemade tools. I heated the solution in the bottom half of an old stainless steel water bottle and I stirred the solution using a stainless steel scoop from an old chemistry kit.
I placed my makeshift pot on a stove with a coil burner and heated the solution until it was nearly boiling.
Then I added the sodium sulfate.
Followed by a small amount of sodium chloride.
And finally, I added the xanthan gum to gel the solution.
And just like that, I had a cooling pack, which only took a couple weeks to make. It should have taken much less time to make one of these cooling packs, but it took me a considerable amount of time to make mine, given that I had to make the sodium sulfate by combining the reactants, filtering the magnesium carbonate out of the solution, and slowly boiling the sodium sulfate solution until the sodium sulfate became a dry powder.
If you wish to try NightHawkInLight’s recipe, I highly recommend that you buy the sodium sulfate; I only made my sodium sulfate because I was interested in exploring the chemistry and I also wanted a small amount of magnesium carbonate.
I’m definitely going to return to this project when I get the appropriate tools and a much larger amount of sodium sulfate.
Have you made your own cooling pack? How was your experience?
Onward American 