What Happens When Potassium Permanganate and Glycerin Are Mixed?

What Happens When Potassium Permanganate and Glycerin Are Mixed?

Mixing potassium permanganate and glycerin causes spontaneous combustion. The chemical reaction causes purple flames to form in just a few minutes. Adding water speeds up the reaction. This experiment is best for use as a demonstration in a well-ventilated space.

When adding these two chemicals, the amounts used must be limited because mixing a large amount creates a great deal of heat. The University of Washington recommends limiting the glycerin to 3 milliliters and the potassium permanganate to 15 grams. The reaction is much slower with larger crystals of potassium permanganate; if the crystals are too large, combustion does not occur.