Speakeasy Science

Gummy bear chemistry

I couldn’t resist this wonderfully explosive video on YouTube showing the unfortunate end of a red gummy bear when mixed with potassium perchlorate.

I do love to watch a good hissing, sparking chemical reaction. Especially when it’s not me doing the sparking (see earlier blog on the art of setting one’s hair on fire in a Bunsen burner.)

Anyway, potassium perchlorate is made of  potassium (no surprise there), chlorine and oxygen. Its chemical formula is KCLO4, short-hand for saying it contains one atom of potassium, one of chlorine and four of oxygen. Yes, you already figured that out,  I know. But maybe you didn’t know that its lop-sided, oxygen-heavy structure makes it an oxidizer – meaning that it’s highly reactive, poised to unload oxygen into other compounds.

As liquid potassium perchlorate reacts with organic compounds like sugar, the carbon from the sugar combines with the reactive oxygen to form a fizzing  blast of carbon dioxide. Cane sugar creates a low-level explosion; the concentrated corn sugars in gummy bears are even more reactive, setting off that wonderful model rocket-like chemical blast you see in the video.

Actually, potassium perchlorate once was used in rocket fuel. These days, manufacturers prefer a more powerful and more explosive oxidizer, ammonium perchlorate.  Much more explosive – if you have a couple minutes, here’s a video showing what happens in a factory when things go wrong with that compound.

Our friend, potassium perchlorate, is better suited these days to making  firecrackers (mixed with powdered aluminum.) And, of course, it’s just what’s needed if you want to blow up a gummy bear.