Pembakaran Magnesium dalam Es Kering

Magnesium terus terbakar dalam karbon dioksida padat, mereduksi CO₂ menjadi karbon

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

Tujuan

Demonstrasikan bahwa magnesium dapat mereduksi karbon dioksida, menantang kesalahpahaman bahwa CO₂ selalu memadamkan api.

Latar Belakang

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.

Peringatan Keselamatan

  • 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

APD yang Diperlukan

goggles gloves lab_coat face_shield

Bahan

  • 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

Peralatan

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

Prosedur

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 menit 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 menit
3

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

2 menit 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 menit
5

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

3 menit 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 menit 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 menit

Hasil yang Diharapkan

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.

Pembersihan

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

Detail

Kategori
Classroom Demonstrations
Tingkat Kesulitan
Advanced (University)
Durasi
25 menit
Perkiraan Biaya
$15,00
Langkah
7
Bahan
3

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Frequently Asked Questions

What is the objective of Pembakaran Magnesium dalam Es Kering?
Demonstrasikan bahwa magnesium dapat mereduksi karbon dioksida, menantang kesalahpahaman bahwa CO₂ selalu memadamkan api.
How difficult is Pembakaran Magnesium dalam Es Kering?
This experiment is rated as Advanced (University). It takes approximately 25 minutes to complete.
What safety precautions are needed for Pembakaran Magnesium dalam Es Kering?
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 Pembakaran Magnesium dalam Es Kering?
The main materials required are: Magnesium ribbon, Dry ice block, Tongs (long-handled).
What results should I expect from Pembakaran Magnesium dalam Es Kering?
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.