Charcoal burns with potassium nitrate

Heated charcoal burns intensively in contact with potassium nitrate

Scientific name: Charcoal is oxidized in contact with potassium nitrate


Oxidation of charcoal with KNO3

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Powdered Charcoal + KNO3 or KClO3

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KNO3 and charcoal reaction

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Kno3 and charcoal

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2:1 KNO3:Charcoal sulfurless bp

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Combustibles in molten KNO3

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Charcoal in Molten Potassium Nitrate

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Wear eye protection and thermal protective gloves. There is a serious fire risk - a fire extinguisher should be ready. Make sure there is nothing flammable nearby.

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

Reaction formula

2KNO3 -[T]→ 2KNO2 + O2

C + O2 → CO2

Step-by-step instruction

This experiment can be done in two ways.

The first way.

  1. Place potassium nitrate and charcoal powder into a trough.
  2. Heat the mixture with a match, or in a hot plate.

The second way.

  1. Place potassium nitrate into a test tube so that a large part of the tube remains unfilled.
  2. Heat the test tube with a burner.
  3. Heat a piece of charcoal by the same burner.
  4. When all of potassium nitrate has melted, put the piece of charcoal into the test tube.

Scientific background

Potassium nitrate decomposes under heating and produces oxygen. Oxygen supports combustion of the charcoal.


Published on 18 March 2015

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