99.95% Pure Magnesium Ribbon: Lab Uses, Properties, Safety & Specifications
Share
Lab-grade magnesium ribbon is a thin strip of 99.95%-pure magnesium metal used in chemistry classes for combustion demonstrations, activity-series and stoichiometry experiments, and Grignard reagent prep. It ignites at ~473°C and burns with a brilliant white flame at ~3,100°C, leaving white magnesium-oxide ash. SciMed sells it direct from $19.99 per 25g / 70 ft roll, with free US shipping on 5-roll bundles and up.
What Is Lab-Grade Magnesium Ribbon?
Magnesium ribbon is a thin, flexible strip of pure magnesium metal (Mg) with a bright silver surface. At 99.95% purity, lab-grade magnesium ribbon is free of impurities that would interfere with chemical reactions, making it the standard material for quantitative chemistry experiments, thermite demonstrations, and metal reactivity studies in high school, university, and professional research settings.
SciMed's Magnesium Ribbon — 99.95% Pure, 25g / 70ft Roll provides a generous supply ideal for classroom and lab use, with consistent ribbon width and thickness for reproducible results.
Chemical Properties
- Symbol: Mg | Atomic Number: 12 | Atomic Mass: 24.305 g/mol
- Melting Point: 650°C (1,202°F)
- Boiling Point: 1,091°C (1,996°F)
- Density: 1.738 g/cm³
- Ignition temperature: ~473°C (883°F) | Flame temperature: ~3,100°C (5,610°F)
- CAS number: 7439-95-4
- Reactivity: Reacts with water (slowly), acids (vigorously), oxygen (burns with intense white flame)
SciMed vs Fisher Scientific / VWR / Sigma-Aldrich / Amazon — how the options compare
| Feature | SciMed | Fisher | VWR | Sigma-Aldrich | Amazon |
|---|---|---|---|---|---|
| Purity | 99.95% | 99.95% | 99.9% | 99.95–99.99% | 90–98% (variable) |
| Single 25g roll | $19.99 | $28–45 | $32–48 | $40–90 | $10–25 (unverified) |
| Bulk 100-roll case | $1,499.99 ($15/roll) | $2,200–$3,800 | $2,400–$3,600 | $3,500–$7,500 | Not standard |
| Account required | No — direct order | Yes | Yes | Yes | No |
| US shipping | Same-day; free on 5+ rolls | 3–5 days | 3–5 days | 3–5 days | Variable |
| COA / SDS | On request | Standard | Standard | Standard | Rarely |
Bottom line: lab-grade 99.95% purity at direct-manufacturer pricing (30–60% below the distributor channel), no institutional account needed, same-day US dispatch, and free US shipping once you order 5 rolls or more. Consumer "magnesium ribbon" from general marketplaces is often 90–95% purity — inconsistent ignition and an off-color flame that ruins classroom demonstrations.
Standard Laboratory Experiments Using Magnesium Ribbon
1. Combustion in Air (Classic Demonstration)
Magnesium burns in air with a brilliant white flame (~3,100°C), producing magnesium oxide (MgO) and small amounts of magnesium nitride (Mg₃N₂). This reaction demonstrates the reactivity series, oxidation reactions, and energy changes. Safety note: Never look directly at burning magnesium without UV-protective goggles — the emitted UV light can cause photokeratitis (welder's flash).
Reaction: 2Mg + O₂ → 2MgO
2. Reaction with Hydrochloric Acid
Magnesium reacts vigorously with dilute HCl, producing hydrogen gas — used to demonstrate metal-acid reactivity, measure reaction rates, and collect gas for property tests (flammability, density).
Reaction: Mg + 2HCl → MgCl₂ + H₂↑
3. Reaction with Water and Steam
Magnesium reacts slowly with cold water but vigorously with steam, producing magnesium hydroxide and hydrogen. Used to demonstrate reactivity-series position and displacement reactions.
4. Determination of Molar Mass (Stoichiometry)
By measuring the volume of hydrogen gas produced when a known mass of magnesium reacts with excess HCl (at measured temperature and pressure), students calculate the molar mass of magnesium using the ideal gas law — a classic quantitative experiment reinforcing the mole concept.
5. Grignard Reagent Preparation (Organic Chemistry)
Clean magnesium ribbon reacts with an alkyl or aryl halide in dry ether or THF to form a Grignard reagent (R–MgX), one of the most important carbon–carbon bond-forming tools in organic synthesis. Ribbon is preferred over turnings for teaching because its surface area and clean silver finish give a reliable, visible initiation.
6. Reduction of Metal Oxides (Displacement)
Magnesium's high reactivity (above carbon in the reactivity series) lets it reduce oxides of less reactive metals: Mg + CuO → MgO + Cu. Used in displacement-reaction demonstrations.
Safety Handling and Storage
- Store in a cool, dry location away from water, acids, and oxidizing agents
- Keep in a sealed container — surface oxidation reduces reactivity over time
- Magnesium fires cannot be extinguished with water or CO₂ (both worsen the reaction). Use a Class D dry-powder extinguisher or dry sand
- Wear UV-protective (welding shade #3+) goggles when performing combustion demonstrations
- Dispose according to local chemical-waste regulations — do not dispose down drains
Frequently asked questions
What purity of magnesium ribbon do I need for teaching?
99.95% is the lab/teaching-grade standard. Below 99%, trace impurities cause inconsistent ignition, variable burn rate, and an off-color flame. Grignard and other research work also want 99.9%+ for reliable initiation.
How much magnesium ribbon is in a 25g roll?
About 70 feet (21.3 m) of continuous ribbon at a 4 mm × 0.2 mm cross-section — roughly 200+ demonstration pieces at 3 cm each, a full semester for several classes.
How much does lab-grade magnesium ribbon cost?
SciMed direct: $19.99 per 25g roll, down to $15/roll at the 100-roll case. Distributors (Fisher, VWR, Sigma-Aldrich) run $28–90 per single roll because of institutional-account markup.
What temperature does magnesium ribbon ignite and burn at?
It ignites at about 473°C (883°F) and burns at roughly 3,100°C (5,610°F) with a brilliant white flame.
Why can't you put out a magnesium fire with water?
Hot magnesium reacts with water to release hydrogen gas, which can accelerate the fire. Use dry sand or a Class D extinguisher — never water, CO₂, or foam.
Do students need special eye protection?
Yes. The burning flame emits intense UV that causes photokeratitis within seconds of direct viewing. Use welding-grade shade #3+ goggles for the demonstrator; students at 2 m+ can use standard safety glasses for indirect viewing.
Is magnesium ribbon restricted for shipping?
For the roll quantities sold here, magnesium ribbon does not trigger DOT/IATA flammable-solid (Class 4.1) restrictions and ships by standard ground/air. Very large bulk (>50 kg) may need freight arrangement.
How long does a roll stay usable?
Stored dry and sealed, 5+ years. A dull, powdery grey surface signals oxidation and reduced ignition reliability.
Can magnesium ribbon be used to ignite thermite?
Yes — 3–5 cm of ribbon is the standard fuse for iron-oxide/aluminum thermite, supplying the ~2,000°C needed. Advanced, supervised use only.
What's the difference between ribbon and turnings for Grignard prep?
Ribbon offers a clean, consistent surface that initiates visibly and reliably — preferred for teaching. Turnings give more surface area for large-scale synthesis but can be harder to judge for beginners.
What is the CAS number for magnesium?
CAS 7439-95-4. SDS and a certificate of analysis are available on request for institutional compliance.
Shop Magnesium Ribbon — 99.95% Pure, from $19.99 · Free shipping on 5+ rolls →
Related magnesium ribbon guides
- Best Magnesium Ribbon for Chemistry Teachers 2026 — Fisher vs VWR vs Sigma-Aldrich vs SciMed
- Magnesium Ribbon for Grignard Reagent Prep — Complete Buying Guide
- Magnesium Ribbon FAQ — 25 chemistry-teacher & lab questions answered
Reviewed by the SciMed Technical Team · Last reviewed: September 1, 2026. Physical and chemical property data cross-checked against the NIST Chemistry WebBook (magnesium, CAS 7439-95-4) and the manufacturer Safety Data Sheet (Sigma-Aldrich magnesium ribbon SDS / ACS reagent references). Always follow your institution's chemical hygiene plan and OSHA laboratory-safety standards.