“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;
  • burn­er.

Step-by-step in­struc­tions

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.

Pro­cess­es de­scrip­tion

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.

Safe­ty pre­cau­tions

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.