Magnesium Fires

Hazards

Magnesium burns extremely bright. Do not look directly at the flame.

Chemicals and Solutions

magnesium ribbon

Materials

  • hotplate
  • two 1L Erlenmeyer flasks
  • water
  • dry ice
  • tongs
  • bunsen burner and matches
  • wood splints

Procedure

  1. Make a steam bath by heating a small amount of water in an Erlenmeyer flask on a hot plate.
  2. Holding a wooden splint with tongs, ignite it and place it in the boiling water. It will extinguish. Repeat this step using magnesium ribbon. Magnesium burns in steam.
  3. Place dry ice in the second erlenmeyer. Holding a wooden splint with tongs, ignite it and place it in the carbon dioxide vapor. It will extinguish. Repeat this step using magnesium ribbon. Magnesium burns in carbon dioxide. Look for the black specks of carbon formed.

Discussion

Magnesium burns in substances that normally extinguish flames. It burns in boiling water and carbon dioxide:

\( \ce{ Mg + H2O -> MgO + H2 } \)

\( \ce{ 2Mg + CO2 -> 2MgO + C } \)