- Put about 1 gram of potassium permanganate in the test-tube.
- Clamp it on the stand.
- Heat the test tube with a gas burner.
- Hold the smoldering splint to the mouth of the test tube.
- The splint flares up.
Smoldering splint flares up.
Scientific name: Potassium permanganate decomposes under heating.
Wear eye protection goggles and gloves. Reaction products are toxic. Avoid contact with produced substances.
Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.
2KMnO4 → K2MnO4 + MnO2 + O2
In the laboratory oxygen is produced by thermal or catalytic decomposition of oxygen contained substances. Heating potassium permanganate gives potassium manganate, magnesium oxide and oxygen. Since oxygen supports burning, splinter flashing is a common test on the presence of oxygen.