Weird Chemical Reaction! How to Make the ‘Pharoah’s Serpent’

The Pharoah’s Serpent is one of the coolest chemical reactions ever, it looks like a monster coming out of hell! Used as a firework in Germany from 1981 it was eventually banned due to the toxic chemical byproducts released.

But how does this seemingly impossible reaction occur? Firstly we need to make Mercury (11) thiocynate and then we need to set it on fire. The process is long and dangerously toxic but well worth the wait for this weird and wonderful reaction!

Making Mercury (11) thiocynate requires Potassium thiocynate, elemental mercury and nitric acid. The end result is a paste -like substance you can mold into however big a mound you like and leave to dry. Setting this product on fire creates the crazy weird chemical reaction you’ve just seen.

But warning, don’t ever try this at home, you need serious waste disposal spots and a fume hood or to be outside, because while the ‘Pharoah’s Serpent’ can’t really hurt you the toxic gas coming off the reaction could kill you!

James Carson graduated from the University of York with a degree in English and History and have a keen interested in both World Wars and popular science - particularly space.