Dead cockroach dissolves in piranha solution

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I bet my labmates that piranha solution would completely dissolve a dead cockroach we found in the hallway. As you can see, I won. There isn't much to see after about 1:10. • Piranha solution is extremely dangerous to handle and dispose of. Do not attempt this without expertise. • I promise the roach was dead for a long time. It looks like it's moving at the beginning because of air currents in the hood. • ---------------------------------------------------------------------------------------------------------- • What's going on? • Piranha solution is used for cleaning inert metal surfaces because is great at breaking down organics. This happens in two stages. First there is a rapid dehydration (removal of hydrogen and oxygen) by the sulfuric acid. Then it carbonizes the organic molecules. In other words, piranha can break up long chain organic molecules by effectively pushing an oxygen into carbon-carbon bonds to disrupt them. The material that makes up cockroache's exoskeleton is chitin ( long-chain acetylglucosamine), which is such a macromolecule. • Piranha solution is stoichiometrically 1:1 sulfuric acid and hydrogen peroxide, but is usually mixed 1:3. We use 50% hydrogen peroxide, but for this I didn't really care about the ratio. This reaction was very vigorous regardless, as piranha sometimes is with organics in large amounts. It is also very exothermic, which is why later in the video you can see me touching the beaker to gauge how far along the reaction is. Trust me, it got quite hot. • Not all safety precautions are shown here. This reaction took place in a fume hood and everything was observed through the glass in person. This, as well as inexperience, is why the camera is not very well framed.

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