Demonstration: Gummy Bear Sacrifice:
Energy of Oxidation of Carbohydrates

Description: This demonstration illustrates the vast amount of energy which is available from the oxidation of carbohydrates, such as sugar. An excess of oxygen, generated by the decomposition of sodium chlorate, will react with a gummy bear, releasing a large amount of energy quickly and dramatically.

Materials Needed

• one 25x150 mm test tube
• one ring stand with clamp for test tube
• 5-7 grams sodium chlorate
• Bunsen burner
• one candy gummy bear (any other candy or a wood splint will work)

Hazards: This reaction produces a large quantity of heat, flame, and smoke (mostly water vapor). It should be done in a well ventilated room. Sodium chlorate should be used with caution. It is a strong oxidizing agent, especially when molten. Keep all combustible materials away from the reaction area. Make sure the test tube used is scrupulously clean and the mouth is pointed away from the audience.

Procedure: Set up the stand and clamp, and support the test tube in the clamp in a vertical position. Add 5-7 grams of sodium chlorate to the test tube (about 1 cm in depth). [Note: potassium chlorate can be substituted here, but the sodium chlorate has a lower melting point and requires less initial heating.] Gently heat the tube with the burner until the sodium chlorate is completely molten. Bubbles of oxygen will begin to form. Remove the burner and use crucible tongs to drop in the gummy bear, then stand back! For added piece of mind, the reaction can be performed behind a safety shield.

Disposal: Allow the tube to cool, then remove from the clamp. The tube should be soaked in water for about 15 minutes and then cleaned with a brush to remove the residue. These chemicals may be washed down the drain.

Discussion: When heated, sodium chlorate decomposes, producing sufficient oxygen to ignite the sugar in the gummy bear. Since the oxidation of the sugar is very exothermic, sodium chlorate continues to decompose to oxygen, and the rate of combustion becomes very rapid.



Other carbohydrate materials may be used for this reaction, e.g. an M&M, gum drop or cinnamon heart. The size of the candy and test tube should be matched so that the candy will easily fit into the tube.

REFERENCE: Bob Dayton, Tom Annacone, Lee Meriwether, Princeton Summer Institute, l988 Revised version by Mark Case, CHEM6 TORCH Binder, 1995.