FIREFLIES in a flask experiment

by basco36

Ammonium dichromate (NH₄)2Cr2O7 decomposes when heated yielding green chromium(III) oxide, nitrogen and water vapor. It is a comproportionation reaction where Cr(+6) of Cr2O7^2- gets reduced to Cr(+3) of Cr2O3 oxidising N(-3) of NH4⁺ to N(0) of N₂ gas. This process needs quite a lot of energy to get started and it can be used to simulate a chemical volcano. However, if hot (NH₄)2Cr2O7 is put in contact with NH₃(g) (ammonia), obtained from a saturated NH₄OH solution, the comproportionation is much faster as it can be seen on this video...