“Fire storm” experiment
How to make fireflies in a flask
Chrome oxide (III) scatters red sparks in a flask filled with ammonia.
Reagents and equipment:
- aqueous solution of ammonia (10 ml);
- chrome oxide(III) (5—10 g);
- 1 1-liter flask;
- burning spoon;
Pour ammonia into the flask. Carefully rotate the flask to fill the air space in the flask with ammonia. Place a little chrome oxide(III) on to a burning spoon and heat it with a burner. As a result, sparks will start to fly in the flask.
The heated chrome oxide will act as a catalyst for the oxidation of ammonia. On its surface, the ammonia is oxidized by the oxygen in the air.
4NH₃ + 5O₂ → 4NO + 6H₂O
2NO + O₂ → 2NO₂
Energy is released in the reaction which heats the particles of chrome oxide (III) even more, causing them to glow.
Wear protective glasses and gloves. The experiment should be carried out in a fume hood or well-ventilated room. Follow general safety recommendations. Chemical experiments must be carried out in full compliance with the legislation of your country.
Warning! Substances of this experiment are toxic and highly dangerous for your health. Do not try this at home. Only under professional supervision.