GUMMI BEAR EXPLOSION DEMONSTRATION
Purpose: This demo gives an example of an extremely exothermic reaction. It is also an example
of a decomposition reaction that occurs rapidly when a catalyst (heat) is used. In addition, it
provides the opportunity to apply the glowing splint test to test for the presence of oxygen.
Equipment and Materials:
KClO3 (Potassium Chlorate) Gummi Bears
Retort Stand
Safety Shield
Pyrex Test Tube (Use only Pyrex Test Tubes)
Scoopula
Wooden Splint
Flint Lighter
Test Tube Clamp
Bunsen Burner
Safety Considerations: Because this reaction is extremely exothermic, be sure to take careful
consideration for the points mentioned below.
Ensure that the safety shield is between the apparatus and your students
Check the Pyrex test tube for any defects. If any flaws (small cracks, etc.) are present, refrain
from using it.
Make sure that you wear safety shield and a lab coat.
Be sure to point the test tube away from you and your students.
Procedure:
Set up a test tube clamp onto a retort stand. Place the safety shield between the apparatus and your
students. Using a scoopula, place approximately 1cm of KClO3 in the bottom of the test tube.
Place the test tube into the clamp, and raise the clamp high enough so that a Bunsen burner
can be placed underneath. Be sure that the mouth of the test tube is facing away from your
students. Light the Bunsen burner with the flint lighter, and place it under the base of the test
tube.
Once the solid KClO3 has begun to liquefy, test for the presence of oxygen using the glowing
splint test. If the test has worked, and the gases ignite the glowing splint, you can remove the
Bunsen burner and turn it off. Quickly, use the scoopula to place the Gummi Bear into the
test tube, and move away from the test tube. The heat given off from the reaction will now
cause the Gummi Bear to explode.
***Questions to be asked before the demo***
1. What is a decomposition reaction? What is a synthesis reaction? What is a combustion
reaction?
2. Discuss and balance the chemical equation for this reaction.
__ KClO3(s)  __ KCl (s) +__ O2 (g) and then
__C11H22O11 + O2  CO2 + __H2O + 32C(s)
3. What gas are we testing for the presence of when we do the wood splint test?
4. What is the difference between an exothermic and an endothermic reaction?
***Questions to be asked during the demo***
1. Why do we use a Bunsen burner in this reaction?
2. Why do we do the glowing splint test before putting the Gummi Bear into the test tube?
***Questions to be asked after the demo***
1. What caused the Gummi Bear to explode?
2. Why do we use a catalyst for some reactions? In this demo, the catalyst is not a molecule, what
is it?
3. Examine what the products are. Do you think a combustion reaction occurred here?
Explanation:
The chemical equation of the reaction for this demo is:
2 KClO3(s)2 KCl (s) + 3 O2 (g) and then 3C11H22O11 + O2  CO2(g) + 33H2O(g) + 32C(s)
The symbol “”, or the word “heat” can be written above the arrow to show that heat is used as a
catalyst.
The heat from the Bunsen burner is used as a catalyst to increase the rate of reaction. The glowing
splint will re-light once there is a presence of oxygen, meaning that the decomposition
reaction has begun.
Because this reaction is extremely exothermic, the heat given off of the reaction causes the sugar
in the Gummi Bear to explode into a marshmallow-like substance.
Reference: Dr. Eva Waller. Holy Cross Secondary School, Kingston, ON.
Link to the Curriculum:
This demo can relate to both the Grade 10 and Grade 11 Chemistry curriculum in the following
ways:
Decomposition reactions
Exothermic reactions (Heat as a non-visible product)
Balancing chemical equations
Testing for the presence of oxygen (glowing splint test)
Catalysts