Has it been a year already? Well it is time for my halloween demos. This years halloween show will have 250 pounds of solid CO2 (dry ice) for my chemistry demonstrations. This reaction is between metallic magnesium and carbon dioxide. Magnesium reacts with oxygen in the air to form magnesium oxide, but when the only source of oxygen is from CO2 the reaction becomes much more energetic. The products are white magnesium oxide and blck carbon.
Cut a block of dry ice into 2 large bloks with a hand saw
Carve a 1 inch deep divit in one of the blocks
Add a few grams of Magnesium metal to this block
Extend a fuse of magnesium out of this pile. The Mg will not light in the block (no Oxygen)
Once lit allow the reaction to proceed. It may take a few tries. Once lit, cover the dry ice with the other block. Stand back.
A safety shield is highly recommened for classroom demonstrations.
2Mg + CO2--> 2MgO + C
1. Handle the dry ice with protective gloves.
2. Remove any combustible items because some burning Mg turnings may fly out.
3. Warn students not to stare directly at burning Mg. Dark colored safety glasses can be worn which absorb most of the UV light.