Magnesium in Dry Ice

Materials Needed

• 2 slabs of CO₂ (order from Airgas dry ice)
• Kiln brick (obtain from Dave Plasket)
• Warm water
• Mg wire
• Mg turnings
• Bunsen burner
• Airline (for air supply)

Procedure

Preparation of CO₂ Slabs

1. Create Wells:

• Obtain two slabs of CO₂.
• In the center of each slab, make wells approximately 3 inches across and about ½ the depth of the slab.
• Start by adding a drop of warm water to soften the ice.
• Use air from the airline to help form the well, applying warm water as needed.
• Caution: Do not attempt to chisel a hole in the ice, as this will split the slab.

Assembly

2. Set Up the Experiment:

• Place one slab of dry ice on a kiln brick.
• Create a wick from Mg wire by folding it into a zigzag pattern.
• Place the wick into the well of the dry ice slab.
• Fill the well with Mg turnings.

Ignition

3. Ignite and Observe:

• Ignite the wick with a Bunsen burner.
• Once the Mg has started to burn, quickly invert the other slab over the Mg, ensuring the well is positioned over it.
• Allow the reaction to proceed.

Demonstration

4. Comparison:

• Be sure to demonstrate what a regular fire does in CO₂ to illustrate the differences in combustion.

Safety Precautions

• Conduct the experiment in a well-ventilated area or fume hood.
• Wear appropriate personal protective equipment (PPE), including gloves and goggles.
• Handle dry ice carefully to avoid frostbite.

This experiment demonstrates the combustion of magnesium in a carbon dioxide environment, providing insights into the behavior of fire and combustion in different atmospheric conditions.