Chemical Hydra

How to make chemical monster using ammonium dichromate

A chem­i­cal Hy­dra ap­peared just in time for our Hal­loween par­ty!

Safe­ty pre­cau­tions

Do not try this at home! Per­form this ex­per­i­ment only un­der pro­fes­sion­al su­per­vi­sion.

Equip­ment and reagents

  • 15g am­mo­ni­um ni­trate;
  • 3g urotropine;
  • 15g am­mo­ni­um dichro­mate;
  • porce­lain cup;
  • 1mL kerosene;
  • wood­en stick.

Step-by-step in­struc­tions

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!

Process de­scrip­tion

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!