Sodium Peroxide
Properties
| State | Solid (powder or granular) |
| Color | Yellowish-white |
| Solubility | Reacts with water (produces NaOH and H2O2) |
| Melting Point | 460 °C (decomposes above 657 °C) |
| Boiling Point | Decomposes before boiling |
About Sodium Peroxide
Sodium peroxide is the yellowish powder you get when you burn metallic sodium in dry oxygen at around 350 to 450 °C, and it is the reason a fire involving sodium and a Class D extinguisher is non-trivial — water makes things worse, not better. The peroxide anion O2 2- gives Na2O2 its character: it is simultaneously a strong oxidizer and a powerful base, and it reacts with water in a single exothermic step to give NaOH and H2O2 (Na2O2 + 2H2O -> 2NaOH + H2O2). The hydrogen peroxide that forms can decompose further, releasing oxygen and enough heat to ignite anything organic in the area. Industrially, the most distinctive use is as a fusion reagent for analytical chemistry: refractory minerals like chromite, zircon, and certain silicate ores that shrug off concentrated HF or aqua regia will dissolve cleanly in molten Na2O2 at about 500 °C in a nickel or zirconium crucible, after which the melt is taken up in dilute acid for ICP-OES or ICP-MS. Smaller volumes show up in pulp bleaching and as an oxygen-generating component in self-rescuer breathing devices used in mine emergencies.
Where you'll encounter it
If you have ever opened a self-contained self-rescuer (SCSR) on a mine safety course, the white granular material packed around the breathing chamber is sodium peroxide or its potassium analog KO2. Both react with the CO2 and water vapor in your exhaled breath to release O2 in a 2:1 stoichiometry — one molecule of CO2 in, one molecule of O2 out — giving a roughly closed-loop oxygen supply for 30 to 60 minutes underground. Submarines used the same chemistry through World War II. In the analytical lab, you encounter Na2O2 fusion when you need total digestion of a chromium ore for trace-element analysis: the bench-top alternative is a nickel crucible, a Bunsen burner, careful weighing of the sodium peroxide flux, and an unmistakable orange glow as the chromite dissolves into a green sodium chromate melt.
Common Uses
- Fusion reagent for total digestion of chromite, zircon, and refractory silicate ores in nickel crucibles
- Oxygen source in self-contained self-rescuer breathing devices for mine and submarine emergencies
- Bleaching agent in chemical pulping and specialty paper production
- Strong oxidizer for converting alcohols to carboxylic acids in laboratory synthesis
- Co-reactant for generating hydrogen peroxide in situ during industrial oxidation steps
- CO2 absorber in closed-circuit breathing apparatus where Na2O2 + CO2 -> Na2CO3 + 1/2 O2
- Historical bleaching agent for ivory, bone, sponges, straw, and silk in 19th-century industry
Safety Information
Strong oxidizer and severe corrosive. GHS classifications: H271 (may cause fire or explosion; strong oxidizer), H314 (causes severe skin burns and eye damage), H290 (may be corrosive to metals). No OSHA PEL is listed for Na2O2 specifically, but the reaction product NaOH is regulated at 2 mg/m3 ceiling and H2O2 has an OSHA PEL of 1 ppm TWA. Reacts violently with water, organic solvents, finely divided metals, and reducing agents — a small spill onto a paper towel can ignite spontaneously. Store in airtight metal containers under dry inert atmosphere, away from any organic material, and segregated from acids. Spills are smothered with dry sand or vermiculite, never wetted.
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.