Self Carving Pumpkin with Carbide

Introduce this demonstration by doing the calcium carbide explosion first.  Pre-carve a pumpkin with simple shapes and reinsert the carved pieces back in the pumpkin.  Pour about 50 mL of H₂O₂ into the flesh of the pumpkin (catalase, an enzyme in the pumpkins' flesh, generates excess oxygen as the H₂O₂ is broken down into H₂O and O₂).  Insert a small dish of water (tuna fish can half full of water) into the pumpkin.  Add 5-7 chunks (size of 3 peas) of calcium carbide ) in the dish of water.  Bore a small hole in the back of the pumpkin that you will be able to insert a piezoelectric starter - keep hole covered until ready to ignite.  Wait 90 - 120 seconds.  Ignite.  

Caution:  Wear safety goggles and ear protection. 

Concepts:  Combustion, Write a chemical equation

Time Required:  15 minutes

Chemicals Provided  calcium carbide, water