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Dancing Gummy Bear

NSF Mentors, Anthony Butterfield  |  Created: January 27, 2011  |  Last Modified: December 1, 2011

Summary:

Dancing Gummy Bear This demonstration displays the strength of Oxidation-Reduction reactions. When a gummy bear is mixed with molten potassium chlorate, its sugar breaks down into CO2 and H2O, while the potassium chlorate becomes potassium chloride. The reaction is vigorous and creates a great deal of heat and an impressive purple flame.

IMPORTANT!!! Under no circumstances should an unsupervised minor perform the procedures described herein. All the following described experiments and methods should be supervised by an adult who is completely familiar with and takes full responsibility for all possible hazards.

General Information:
Main Curriculum Tie: Chemistry
Additional Curriculum Ties: Experimental Safety
Career Connections: Chemistry, Chemical Engineering
Mean Time Frame: 5
Group Size: Large Group
Student Prior Knowledge: Chemical reactions, Oxidation States.

 

Essential Questions

  • What is an Oxidation-Reduction reaction?
  • Why is this particular reaction so strong?
  • Why are Oxidation-Reduction reactions important?

 

Bibliography

  1. Sullivan, D.M., "The Howling Gummy Bear"; Journal of Chemical Education, vol. 69(4), pp. 326, (1992).

 

Materials & Methods

  • Gummy bears.
  • Potassium chlorate (Sodium Chlorate will work as well).
  • Pyrex test tube.
  • Ring stand and clamp.
  • Tongs.
  • Bunsen burner.
  • Safety Goggles and Shield.
  • Nitrile Gloves

 

Background for teachers

Oxidation-Reduction reactions are a critical part of Chemistry and life. These reactions are very important in industry and also in our bodies. Oxidation-Reduction reactions control cellular respiration by taking glucose and oxygen and making CO2 and H20.

C6H12O6 + 6O2 ? 6CO2 + 6H2O

In this reaction Carbon goes from an oxidation state of zero to +4 while the O2 is reduced from zero to an oxidation state of -2.

For our demonstration we are taking potassium chlorate and mixing it with sucrose to create CO2 and H2O. When heated, potassium chlorate breaks up to form potassium chloride and oxygen.

2KClO3(s) ? 2KCl(s) + 3O2(g)

When mixed with sucrose it causes the Oxidation-Reduction reaction that creates carbon dioxide and water while precipitating potassium chloride salt.

C12H22O11(s) + 3O2 ? 9C(s) + 3CO2(g) + 11H2O(l)

 

Videos

  • YouTube Videos:
    • http://www.youtube.com/user/UnvUtahChenEng

 

Intended Learning Outcomes

Students should learn:
  1. How Oxidation-Reduction reactions happen.
  2. What is oxidized and reduced in the specific reaction.
  3. Proper safety techniques for dangerous experiments.

 

Instructional Procedures

  1. Setup the ring clamp and test tube so that the test tube is angled at approximately at a 45 degree angle. Note that the reaction will produce some smoke and care should be taken to avoid tripping fire sprinklers. Also, sometimes particles are ejected from the test tube and the mouth should be pointed away from the audience or anything flammable.
  2. Put enough potassium chlorate into the test tube (approx PUT IN g) so that when melted it is about 1 cm deep.
  3. Heat the potassium chlorate with a Bunsen burner until it is completely molten.
  4. Carefully drop the gummy bear (or other small sugar-containing object) into the test tube. Note: Do not use granulated sugar; the increased surface area may cause the reaction to proceed too quickly and pose an explosion hazard.
  5. Observe the reaction from a safe distance.

 

Optional Activities & Extensions

  • Compare the heat release with different brands of gummy candy and relate to their caloric content.
  • Compare the response using gummy candy verses peanuts.
  • Add metal compounds to produce different colored flames.

 

Assessment Plan

Possible questions to be used for assessment:

Select the check box next to the questions you wish to use; then hit the submit button at the bottom of the page to create your worksheet.

Select all

Q1. What is oxidized in this reaction?

- A1.

Carbon.

 

Q2. What is reduced in this reaction?

- A2.

Oxygen.

 

Q3. How many electrons are transferred?

- A3.

Four.

 

Q4. What are the oxidation numbers for every element in the reaction?

- A4.

Carbon (-4) Hydrogen (+1) Oxygen (-2) Potassium (+1) Chlorine (-1)

 

Q5. Is this reaction exothermic or endothermic?

- A5.

Exothermic.

 

    

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If you have a question regarding this teaching module or any other,
please feel free to contact Professor Butterfield, tony.butterfield@utah.edu.