Products
Pure potassium permanganate is available in pharmacies and drugstores.
Structure and properties
Potassium permanganate (KMnO4, Mr = 158.0 g/mol) exists as a dark purple to brownish black, granular powder or as dark purple to nearly black, metallically lustrous crystals and is readily soluble in boiling water. The substance decomposes on contact with various organic substances and there is a risk of explosion with some substances (see below). The oxidation number for the manganese is +7. Structure: K+MnO4–
Effects
Potassium permanganate (ATC D08AX06, ATC V03AB18) is a strong oxidizing agent. It has disinfecting, oxidizing, deodorizing, and astringent properties.
Indications for use
- Potassium permanganate was used medicinally in the form of a highly diluted solution for wound cleaning and disinfection and for mouthwashes, among other uses. Today, it is rarely used.
- Skin diseases, fungal infections
- As a reagent, for organic synthesis.
- As an antidote
- In veterinary medicine, for ornamental fish.
For chemical experiments (redox reaction): if a few drops of glycerol are added to potassium permanganate, a violent exothermic reaction occurs with a violet flame and a spark and heat:
- 14 KMnO4 (potassium permanganate) + 4 C3H8O3 (glycerol) 7 K2CO3 (potassium carbonate) + 7 Mn2O3 (manganese(III) oxide) + 5 CO2 (carbon dioxide) + 16 H2O (water)
Abuse
When dispensing must take into account that potassium permanganate is suitable for the production of explosive and flammable compounds. Young people also dye fountains with it for fun.