Ammonium Dichromate Volcano

With just one chemical you can create a realistic-looking chemistry volcano. The chemical is called Ammonium Dichromate and here is how to do the experiment:

Key Takeaways

  • The volcano is made up by a pile of ammonium dichromate
  • While the ammonium dichromate decomposes, it gives off orange sparks and throws the green chromium(III) oxide crystals into the air, producing an effect that looks like a miniature volcanic eruption
  • Dichromate salts are very toxic and carcinogenic!

How to make a chemical volcano

Only perform this experiment, if you can guarantee safety and safe disposal! Chromium compounds are often carcinogenic and very toxic to the environment.

 

Start the chemistry volcano

Form a small pile of ammonium dichromate salt in the middle of the aluminum foil. When ready ignite the powder at the top of the pile. The reaction should soon catch up on itself. 

How does the Dichromate Volcano work?

Ammonium dichromate, (NH4)2Cr2O7, decomposes when heated to produce chromium(III) oxide [Cr2O3], nitrogen gas, and water vapor:

(NH4)2Cr2O7(s)  ——>  Cr2O3(s)  +  N2(g)  +  4H2O(g)

While the ammonium dichromate decomposes, it gives off orange sparks and throws the green chromium(III) oxide crystals into the air, producing an effect that looks like a miniature volcanic eruption.

The chromium(III) oxide crystals that are produced are “fluffier” than the original ammonium dichromate crystals, and even though a lot of the mass of the starting materials escapes as vapor, the product looks like a larger amount of material.”  by Angelo.edu 

Safety & Disposal

Chromium salts are irritating to the skin and respiratory tracts, and are also carcinogenic.  (The ammonium dichromate contains chromium in the hexavalent, Cr6+). Only recreate this experiments if you can assure matching safety & disposal requirements.

The best way to do this demonstration is on a large piece of aluminum foil, which can then be used to wrap up the chromium salts produced.

GHS H&P: H(272301312314317334330340350360FD372410) – P(201210260280304+340+310305+351+338)

The use of this instruction and the information provided therein takes place at the user’s own risk.

Experiment Video