Sodium peroxide is an inorganic compound with the formula Sodium2Oxygen2. This yellowish solid is the product of sodium ignited in excess oxygen.[
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Properties
Sodium peroxide crystallizes with hexagonal symmetry.[Lewis, R. J. Sax's Dangerous Properties of Industrial Materials, 10th ed., John Wiley & Sons, Inc.: 2000.]
- 2 Na2O2 → 2 Na2O + O2
Preparation
Commercially, sodium peroxide is produced from the elements in a two-stage process. First sodium is oxidized to sodium oxide:[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.]
Subsequently, this oxide is treated with more oxygen:
This was the method by which the substance was discovered in 1810 by Joseph Louis Gay-Lussac and Louis Jacques Thénard, as well as how it was for the first time commercially made by Hamilton Castner in the 1890s.
It may also be produced by passing ozone gas over solid sodium iodide inside a platinum or palladium tube. The ozone oxidizes the sodium to form sodium peroxide. The iodine can be sublimed by mild heating. The platinum or palladium catalyzes the reaction and is not attacked by the sodium peroxide.
The octahydrate can be produced by treating sodium hydroxide with hydrogen peroxide.
Uses
Sodium peroxide hydrolysis to give sodium hydroxide and hydrogen peroxide according to the reaction[
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- 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[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:
- Na2O2 + CO2 → Na2CO3 + O2
- Na2O2 + H2O + 2 CO2 → 2 NaHCO3 + O2
It is thus particularly useful in scuba gear, submarines, etc. Lithium peroxide and potassium superoxide have similar uses.
Sodium peroxide was once used on a large scale for the production of sodium perborate, but alternative routes to that cleaning agent have been developed.[
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