Glycerol and KMnO4

 

 

Summary:  A puddle of glycerol is poured on a pile of potassium permanganate in a porcelain cup.  After about 30seconds, the reaction bursts into purple flame. 

Hazards: 

Potassium permanganate is a strong oxidizer. 

Chemicals and Solutions: 

15 g potassium permanganate

2-3 mL glycerol

Materials: 

porcelain dish

Procedure: 

Place KMnO4 in dish

Add glycerol on top of potassium permanganate

Stand back. After 30 sec. the reaction mixture will burst into a purple flame

If larger crystals of potassium permanganate are used the reaction is much slower.  (For this reason you can use this demonstration while teaching kinetics.)

Hint: 

This reaction can be delayed if the crystal size of the potassium permanganate is large.

Discussion: 

The reaction:

14KMnO4 + 4C3H5(OH)3 ----> 7K2CO3 + 7Mn2O3 +5CO2 +16H2O

 

 

To schedule a demonstration, please send an email to the demonstration lab.

 

Contact:

Eric Camp

Lecture Demonstration Technician

Bagley Hall 171

(206) 543-1606

ericcamp@uw.edu

 

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