Barium Nitrate
Properties
| State | Solid (white crystalline powder or crystals) |
| Color | White |
| Solubility | Soluble in water (87 g/L at 20°C); insoluble in ethanol |
| Melting Point | 592°C |
| Boiling Point | Decomposes above 592°C |
About Barium Nitrate
Barium nitrate is the soluble barium salt that lights up green fireworks, and the chemistry it provides is unusually compact: the barium delivers the green color (atomic Ba emission is concentrated in the 510–550 nm range, peaking at 524 nm), and the nitrate delivers the oxidizer that sustains combustion in the same compound. Most other pyrotechnic green colorants need a separate oxidizer mixed in — barium chlorate or barium nitrate are the only common single-compound sources of green flame color plus oxygen. The atomic emission lines that produce the green come from thermally excited barium atoms, with the most intense line at 524 nm (5d6s¹P1 → 6s²¹S0 transition); cooler flames give a more yellow-green color, hotter flames push toward pure green and even a hint of blue. The nitrate decomposition that drives combustion goes through 2 Ba(NO3)2 → 2 BaO + 4 NO2 + O2 above 600 °C, releasing both the oxidizer (O2) and intermediate NO2 that participates in the radical chemistry of the flame zone. Barium nitrate is also the standard precursor for barium oxide and barium peroxide synthesis, and it appears in some military signal-flare and tracer-round compositions where green visibility through smoke is the design priority. As with all soluble Ba²⁺ sources, it carries the same potassium-channel-blocking toxicity profile that makes BaCl2 dangerous.
Where you'll encounter it
If you've watched a fireworks display and seen a green starburst, the chemistry was almost certainly barium nitrate plus a fuel like sulfur or shellac. The standard amateur-pyrotechnic green-star formulation runs barium nitrate at 50–60% by mass, sulfur at 10–15%, and a fuel like potassium chlorate or aluminum powder rounding out the rest. In a teaching context, barium nitrate is the substrate for the classic flame-test demonstration — wet a clean nichrome wire with concentrated solution, hold it in a Bunsen burner flame, and the green color is visible across the lecture hall. Outside pyrotechnics, the salt finds a quieter career as the precursor for barium peroxide (used in glassmaking and as a curing agent for some polymer systems) and as one of the analytical reagents for sulfate gravimetric analysis when chloride needs to be excluded from the sample.
Common Uses
- Green-flame colorant and oxidizer in pyrotechnic compositions
- Precursor for barium oxide and barium peroxide manufacture
- Sulfate-precipitation analytical reagent in chloride-sensitive matrices
- Component of military signal flares and tracer-ammunition formulations
- Specialty ceramic-glaze and optical-glass production
Safety Information
Toxic by ingestion (oral LD50 ~150 mg/kg in rat) — the same potassium-channel-blocking mechanism that makes other soluble Ba²⁺ salts dangerous applies here. The nitrate component adds an oxidizer hazard: bulk material in contact with reducing organics can ignite under shock or heat, which is why pyrotechnic formulations are mixed in small quantities under controlled conditions and never stored as pre-mixed compositions. Aquatic toxicity is significant. GHS H272, H301, H332, H410.
This safety summary is for educational reference only and may not be complete. It is not a substitute for Safety Data Sheets (SDS), medical advice, or professional chemical safety guidance. Always consult appropriate SDS and qualified professionals before handling chemicals.