Calcium Carbide Explosion

Demonstrate the chemical reaction of calcium carbide and water producing acetylene (ethylyne) gas.  Add a few chunks (size of three peas) to a clean 500 mL beaker filled with 200 mL water.  The carbide reacts with water to produce acetylene gas.  Light a match above the beaker and the acetylene gas will be ignited. It can be ignited numerous times...note that more carbon builds up each time as not enough oxygen remains.  Incomplete combustion occurs and you will generate soot (carbon). 

Concepts:  Combustion, Write a chemical equation

Time Required:  15 minutes

Chemicals Provided  calcium carbide, water