Yellow Powder

Powerful explosion and blackening of the melting yellow mixture

Scientific name: Explosion of the gunpowder-resembling mixture


Free Range Chemistry 35 - Yellow Powder

by Royal Society Of Chemistry

Yellow Powder

by Dornier335A

Knallpulver (Yellow powder)

by Random Experiments

yellow powder

by TimThePyro

Yellow powder explosion (Knalllpulver explosion)

by Random Experiments International


Wear eye protection goggles. Stand away from the experimental facility. Work away from flammable objects.

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

Reaction formula

unknown, presumably

2 KNO3 + 2 S → K2SO4 + N2 + SO2

K2CO3 → K2O + CO2

Step-by-step instruction

WARNING! This experiment is dangerous! You should NOT perform this at home. ONLY carry out this experiment, if you are a trained chemist, and you understand local safety and legal requirements, which are required to perform such experiments

  1. Pour 300 mg of sulfur, 600 mg of potassium carbonate and 900 mg of potassium nitrate in a teaspoon.
  2. Fix the teaspoon in a stand.
  3. Ignite an alcohol lamp and put it under the spoon.
  4. Observe the melting of the reaction mixture, followed by an explosion.

Scientific background

The exact mechanism of this reaction is unknown. However, you will notice that the mixture resembles gunpowder (potassium nitrate + sulfur + coal). The difference is only in one component (potassium carbonate instead of sulfur). In our view, the role of potassium carbonate in this experiment is as a source of carbon dioxide, which is released by its decomposition and prevents the slow combustion of the reaction mixture (sulfur, in particular) in the air. Due to this fact, after accumulating the necessary activation energy, first the reaction proceeds rapidly and with an explosion. The first reaction proceeds with the formation of a large number of byproducts. Shown only main products.


Published on 30 June 2015

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