Introduction

Catalysis of the decomposition of hydrogen peroxide is demonstrated in a foil-covered florence flask or fancy bottle.  A packet of manganese dioxide catalyst is suspended by a thread inside the neck of the bottle.  When the stopper is removed, the packet falls into the hydrogen peroxide.  The products of the decomposition form a large white cloud above the mouth of the flask. 

Large white cloud above mouth of flask

2H2O2  —MnO2—> 2H2O + O2

 To Conduct Demonstration:

  • Position the covered or opaque bottle in the middle of a piece of bench paper.
  • Pull the stopper out, allowing the MnO2 packet to fall into the flask.

 Safety 

Goggles should be worn. Wear gloves when handling 30% hydrogen peroxide. Reaction produces heat and generates gas quickly and may spatter.