Chemical volcano

A rapid increase in the volume of the substance and color change

Scientific name: Thermal decomposition of ammonium dichromate


ammonium dichromate volcano

Ammonium Dichromate Volcano

by Brandon Albright

Decomposition of Ammonium Dichromate

by Jmu ChemDemos

Decomposition of ammonium dichromate


by chemkerala

Cool chemical volcano experiment - Ammonium Dichromate

by voodoo30x

Thermal Decomposition of Ammonium Dichromate (VI)

by GeneralJazza


Wear eye protection goggles. Work outdoors or in a hood.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

(NH4)2Cr2O7 → Cr2O3 + N2 + H2O

Step-by-step instruction

  1. Pour a few grams of ammonium dichromate onto a tile or into a metal bowl, in a pile.
  2. Ignite the pile from the top using a torch.
  3. Observe the decomposition of ammonium dichromate.

Scientific background

Ammonium dichromate is an unstable substance due to the presence of Cr (VI) in its anion, which is a strong oxidant. Its thermal decomposition emits water in the form of steam, chromium oxide and nitrogen. Chromium oxide has a low density, in addition, the releasing gases loosen it.


Published on 30 June 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst