Glycerol and potassium permanganate
The chemical redox reaction between potassium permanganate and glycerol is often used to demonstrate the powerful oxidizing property of potassium permanganate, especially in the presence of organic compounds such as glycerol. The exothermic (heat producing) reaction between potassium permanganate (KMnO4), a strong oxidizing agent, and glycerol (C3H5(OH)3), a readily oxidised organic substance, is an example of an experiment sometimes referred to as a "chemical volcano".
Potassium permanganate (KMnO4) is a dark violet colored powder. Its reaction with glycerol (commonly known as glycerin or glycerine) (C3H5(OH)3) is highly exothermic, resulting rapidly in a flame, along with the formation of carbon dioxide and water vapor:
Crystalline potassium permanganate (KMnO4) is placed in an evaporating dish. A depression is made at the center of the permanganate powder and glycerol liquid is added to it. The white smoke-like vapor produced by the reaction is a mixture of carbon dioxide gas and water vapor. Since the reaction is highly exothermic, initial sparking occurs, followed by a lilac- or pink-colored flame. When energy or heat is added to electrons, their energy level increases to an excited state. This state is short-lived, and once the electrons release the energy, they return to their normal energy levels. During this process the energy is visibly observed as light. When the reaction is complete, it leaves behind a grayish solid with green regions.
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- "Glycerol and KMnO4". University of Washington Department of Chemistry. Retrieved May 26, 2019.
- Ernest, Z. (April 16, 2014). "Why do different elements make different color flames when you burn them?". Socratic. Retrieved May 26, 2019.
- "Oxidation of glycerol by potassium permanganate". Chemedxchange. Retrieved May 26, 2019.
- Summerlin, L. R. (1988). Chemical Demonstrations : A sourcebook for Teachers. Volume 1. 2nd ed. Washington, DC: American Chemical Society. p. 122. ISBN 978-0841215351.
- Shakhashiri, B. Z. (1983). Chemical Demonstrations, Volume 1: A Handbook for Teachers of Chemistry. University of Wisconsin Press: Madison, Wisconsin: University of Wisconsin Press. pp. 83–84. ISBN 9780299088903.
- Lister, T.; O'Driscoll, C.; Reed, N. (1995). Classic chemistry demonstrations. London, UK: Royal Society of Chemistry. pp. 65–70. ISBN 978-1-87034-338-1.
- Lee, M. "Chemical Volcano". California State University, Northridge. Retrieved July 11, 2019.
- "Chemical Volcano" (PDF). Homi Bhabha Centre for Science Education. Retrieved July 11, 2019.
- "Spontaneous exothermic reaction". The Royal Society of Chemistry. September 2016. Retrieved May 2, 2020.
- Clark, Jim. "Flame Tests". chemguide. Retrieved July 11, 2019.