Chemical Hydra
Channel: MEL Chemistry
Date: 24/10/2019

A chemical Hydra appeared just in time for our Halloween party!
Equipment and reagents: 15g am­mo­ni­um ni­trate, 3g urotropine, 15g ammonium dichromate, porce­lain cup, 1mL kerosene, wooden stick.
Combine 15g am­mo­ni­um ni­trate, 3g urotropine, and 15g am­mo­ni­um dichro­mate in a porce­lain cup. Add a few drops of kerosene and light with a wooden splint. A Hydra rises menacingly from the depths!
Ammonium dichromate intensifies combustion and breaks down along with urotropine and ammonium nitrate to release gases. The decomposition of am­mo­ni­um dichro­mate yields ni­tro­gen N₂, wa­ter va­por, and green chromium(III) oxide. The chromium(III) oxide makes the Hydra green. The large vol­ume of gas­es, plus the sol­id ox­i­da­tion prod­ucts, are the secret to the mix­ture’s “hydra-like” be­hav­ior. You can find similar safe experiments in the “Chemistry of  Monsters” set by MEL Chemistry!
Safety precautions: do not try this at home! Perform this experiment only under professional supervision.