THE INFLUENCE OF A CATALYST ON THE SPEED OF A REACTION
DEMONSTRATION: CATALYTIC DECOMPOSITION OF HYDROGEN
PEROXIDE.
Hydrogen peroxide decomposes very slowly over a period of months releasing
oxygen and water.
Hydrogen
water
+
oxygen
peroxide
If a catalyst like potassium iodide is added the reaction is much more vigorous
The experiment is described below.
The rate of reaction can be determined by measuring the time taken for the froth
(produced by the evolution of oxygen) to get to the top of the measuring cylinder.
NOTE
For really SPECTACULAR results use 50 mls of 100 volume Hydrogen peroxide.
Also try out other potential catalysts such as:
e.g the biological
celery
carrot juice
catalysts
blood
chopped liver
chemical catalysts
manganese dioxide
potassium dichromate
copper oxide
potassium bromide
lead oxide
potassium chloride
FOR THE TECHNICIAN
1 litre measuring cylinder
glass trough
potassium iodide solid
20 vol hydrogen peroxide
HAZARDS
washing up liquid
100 vol hydrogen peroxide
HYDROGEN PEROXIDE
An irritant to the eyes and skin.
Teacher use of 100 vol hydrogen peroxide only