Sodium peroxide is an

inorganic compound In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemi ...

with the formula Na₂O₂. This yellowish solid is the product of sodium ignited in excess oxygen. It is a strong base. This

metal peroxide Metal peroxides are metal-containing compounds with ionically- or covalently-bonded peroxide () groups. This large family of compounds can be divided into ionic and covalent peroxide. The first class mostly contains the peroxides of the alkali and ...

exists in several hydrates and peroxyhydrates including Na₂O₂·2H₂O₂·4H₂O, Na₂O₂·2H₂O, Na₂O₂·2H₂O₂, and Na₂O₂·8H₂O.Harald Jakob, Stefan Leininger, Thomas Lehmann, Sylvia Jacobi, Sven Gutewort. "Peroxo Compounds, Inorganic". ''Ullmann's Encyclopedia of Industrial Chemistry'', 2007, Wiley-VCH, Weinheim. . The octahydrate, which is simple to prepare, is white, in contrast to the anhydrous material.

Properties

Sodium peroxide crystallizes with hexagonal symmetry. Upon heating, the hexagonal

form Form is the shape, visual appearance, or configuration of an object. In a wider sense, the form is the way something happens. Form also refers to: * Form (document), a document (printed or electronic) with spaces in which to write or enter dat ...

undergoes a transition into a phase of unknown symmetry at 512 °C. With further heating above the 657 °C boiling point, the compound decomposes to Na₂O, releasing O₂.Lewis, R. J. ''Sax's Dangerous Properties of Industrial Materials, 10th ed.'', John Wiley & Sons, Inc.: 2000. : 2 Na₂O₂ → 2 Na₂O + O₂

Preparation

The octahydrate is produced by treating sodium hydroxide with hydrogen peroxide. Sodium peroxide can be prepared on a large scale by the reaction of metallic sodium with oxygen at 130–200 °C, a process that generates

sodium oxide Sodium oxide is a chemical compound with the formula Na2 O. It is used in ceramics and glasses. It is a white solid but the compound is rarely encountered. Instead "sodium oxide" is used to describe components of various materials such as glass ...

, which in a separate stage absorbs oxygen:Macintyre, J. E., ed. ''Dictionary of Inorganic Compounds,'' Chapman & Hall: 1992.E. Dönges "Lithium and Sodium Peroxides" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 979. : 4 Na + O₂ → 2 Na₂O : 2 Na₂O + O₂ → 2 Na₂O₂ It may also be produced by passing ozone gas over solid sodium iodide inside a

platinum Platinum is a chemical element with the symbol Pt and atomic number 78. It is a dense, malleable, ductile, highly unreactive, precious, silverish-white transition metal. Its name originates from Spanish , a diminutive of "silver". Pla ...

or palladium tube. The ozone oxidizes the sodium to form sodium peroxide. The

iodine Iodine is a chemical element with the Symbol (chemistry), symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , ...

can be sublimed by mild heating. The platinum or palladium catalyzes the reaction and is not attacked by the sodium peroxide.

Uses

Sodium peroxide hydrolyzes to give

sodium hydroxide Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations and hydroxide anions . Sodium hydroxide is a highly caustic base and alkal ...

and

hydrogen peroxide Hydrogen peroxide is a chemical compound with the formula . In its pure form, it is a very pale blue liquid that is slightly more viscous than water. It is used as an oxidizer, bleaching agent, and antiseptic, usually as a dilute solution (3% ...

according to the reaction : Na₂O₂ + 2 H₂O → 2 NaOH + H₂O₂ Sodium peroxide was used to bleach wood pulp for the production of paper and textiles. Presently it is mainly used for specialized laboratory operations, e.g., the extraction of minerals from various ores. Sodium peroxide may go by the commercial names of ''Solozone'' and ''Flocool''.Lewis, R. J. ''Sax's Dangerous Properties of Industrial Materials, 10th ed.'', John Wiley & Sons, Inc.: 2000. In chemistry preparations, sodium peroxide is used as an oxidizing agent. It is also used as an oxygen source by reacting it with carbon dioxide to produce oxygen and sodium carbonate: : 2 Na₂O₂ + 2 CO₂ → 2 Na₂CO₃ + O₂ It is thus particularly useful in scuba gear, submarines, etc. Lithium peroxide and

potassium superoxide Potassium superoxide is an inorganic compound with the formula KO2. It is a yellow paramagnetic solid that decomposes in moist air. It is a rare example of a stable salt of the superoxide anion. It is used as a scrubber, dehumidifier, and g ...

have similar uses.

References

External links

International Chemical Safety Card 1606
{{oxygen compounds Peroxides Sodium compounds Oxidizing agents