Magnesio Ardiendo en Hielo Seco

El magnesio continúa ardiendo en dióxido de carbono sólido, reduciendo el CO₂ a carbono

Classroom Demonstrations Advanced (University) 25 min ~$15,00

Objetivo

Demostrar que el magnesio puede reducir el dióxido de carbono, desafiando la idea errónea de que el CO₂ siempre apaga incendios.

Antecedentes

Magnesium burns so intensely (over 3000°C) that it can reduce carbon dioxide to elemental carbon. When a burning magnesium ribbon is placed in a cavity carved into dry ice (solid CO₂), it continues to burn brilliantly white, producing magnesium oxide (white powder) and elemental carbon (black specks). This reaction (2Mg + CO₂ → 2MgO + C) dramatically shows that CO₂ is not always an effective fire extinguisher and that thermodynamic favorability depends on the specific reactants involved.

Advertencias de seguridad

  • Burning magnesium is extremely bright — never look directly at it without shade protection
  • Dry ice causes frostbite on contact — never handle with bare hands
  • Perform behind a safety shield
  • Keep a fire-resistant mat underneath
  • Do not attempt to extinguish burning Mg with water — explosion risk
  • Ensure ventilation — CO₂ accumulation in enclosed spaces is dangerous

EPP requerido

goggles gloves lab_coat face_shield

Materiales

  • Magnesium ribbon (30 cm)
    Clean, bright surface
  • Dry ice block (1 kg)
    Solid CO₂ (−78.5°C)
  • Tongs (long-handled) (1)
    For handling dry ice

Equipamiento

Safety shield Fire-resistant mat Chisel or screwdriver (for carving cavity in dry ice) Lighter or matches Welding goggles or #14 shade glass

Procedimiento

1

Using tongs, carve a small cavity (about 3 cm deep) in the dry ice block. Place the dry ice on a fire-resistant mat.

3 min Wear insulated gloves for dry ice
2

Set up the safety shield between the demonstration and the audience. Distribute welding goggles or instruct everyone to look away when ignited.

2 min
3

Light one end of the magnesium ribbon. Once burning, quickly place it in the dry ice cavity using tongs.

2 min Do not look directly at the flame
4

Place another piece of dry ice on top to create a CO₂ atmosphere around the burning magnesium.

2 min
5

Observe: the magnesium continues to burn with an intense white flame inside the CO₂ environment. It does NOT go out.

3 min Maintain safe distance
6

After the reaction, examine the residue: white MgO powder and black carbon specks. Discuss the reaction: 2Mg + CO₂ → 2MgO + C.

8 min Wait for residue to cool completely
7

Discuss implications for fire safety: why Mg fires cannot be extinguished with CO₂, water, or standard fire extinguishers.

5 min

Resultados esperados

The magnesium continues to burn brilliantly inside the dry ice. After the reaction, white MgO and black carbon specks are visible in the dry ice cavity. This proves CO₂ has been reduced to elemental carbon.

Limpieza

Allow all residues to cool and dry ice to sublimate. Sweep up MgO and carbon residue. No chemical waste disposal needed.

Detalles

Categoría
Classroom Demonstrations
Dificultad
Advanced (University)
Duración
25 min
Costo estimado
$15,00
Pasos
7
Materiales
3

Más experimentos

Columna Arcoíris de Densidades 30 min Congelación Instantánea: Agua Subenfriada 120 min Fluido No Newtoniano: Oobleck 20 min Pasta de Dientes de Elefante 20 min Quimioluminiscencia con Luminol 30 min Reacción del Reloj de Yodo 45 min Reacción del Sodio con Agua 25 min Reacción de Termita 30 min Reacción Oscilante de Briggs-Rauscher 40 min Vaso Desaparecedor (Igualación de Índice de Refracción) 15 min

Frequently Asked Questions

What is the objective of Magnesio Ardiendo en Hielo Seco?
Demostrar que el magnesio puede reducir el dióxido de carbono, desafiando la idea errónea de que el CO₂ siempre apaga incendios.
How difficult is Magnesio Ardiendo en Hielo Seco?
This experiment is rated as Advanced (University). It takes approximately 25 minutes to complete.
What safety precautions are needed for Magnesio Ardiendo en Hielo Seco?
Key safety precautions include: Burning magnesium is extremely bright — never look directly at it without shade protection; Dry ice causes frostbite on contact — never handle with bare hands; Perform behind a safety shield.
What materials are needed for Magnesio Ardiendo en Hielo Seco?
The main materials required are: Magnesium ribbon, Dry ice block, Tongs (long-handled).
What results should I expect from Magnesio Ardiendo en Hielo Seco?
The magnesium continues to burn brilliantly inside the dry ice. After the reaction, white MgO and black carbon specks are visible in the dry ice cavity. This proves CO₂ has been reduced to elemental carbon.