Burning Magnesium Ribbon
Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★☆ Some safety precautions required to perform safely
Categories: Chemical Reactions, Combustion, Elements and Periodic Table
Alternative titles: Bright Light Magnesium Reaction
Summary
A strip of magnesium ribbon, when ignited, burns with an intense white flame, producing magnesium oxide. The reaction is highly exothermic and demonstrates how metals can react vigorously with oxygen.
Procedure
- Cut a strip of magnesium ribbon about 10 cm (4 inches) long.
- Hold the ribbon securely with a pair of tongs.
- Place the ribbon into the hottest part of a lighter or Bunsen burner flame until it ignites.
- Step back slightly and observe the bright white light as the magnesium burns and forms a white powder of magnesium oxide.
- Allow the ash to cool before disposal.
Links
Burning magnesium ribbon - DonoChem:
Chemistry Demo: Burning Magnesium - Dr. B's Chemistry:
📄 Burning Magnesium - LibreTexts Chemistry: https://chem.libretexts.org/Ancillary_Materials/Demos_Techniques_and_Experiments/Lecture_Demonstrations/Burning_Magnesium
Variations
- Compare burning magnesium ribbon to burning other metals such as iron wool.
- Place burning magnesium in a controlled container of carbon dioxide to show that it continues to burn, forming magnesium oxide and carbon.
Safety Precautions
- Wear safety goggles with UV protection; the bright flame produces ultraviolet light that can damage eyes.
- Do not look directly at the burning magnesium; view indirectly.
- Keep away from combustible materials.
- Handle with tongs; do not touch magnesium during or after burning.
- Do not attempt to extinguish magnesium with water or carbon dioxide, as these can intensify the fire. Use only Class D fire extinguishers or cover with dry sand.
- Do not allow children to perform this experiment.
Questions to Consider
- Why is magnesium able to burn so brightly in air? (Magnesium atoms release large amounts of energy when reacting with oxygen, forming MgO.)
- What type of reaction is burning magnesium? (A combustion reaction and also a redox reaction: magnesium is oxidized, oxygen is reduced.)
- Why can’t water or carbon dioxide be used to extinguish a magnesium fire? (Magnesium reacts with water to release hydrogen gas, and with CO2 to release carbon—both reactions intensify the fire.)
- What is the balanced equation for burning magnesium in air? (2Mg(s) + O2(g) → 2MgO(s).)
- Why is the reaction exothermic? (Energy is released as strong ionic bonds form between Mg2+ and O2− ions in magnesium oxide.)