Sodium peroxide, Na
2O
2, is the normal product when sodium is burned. It is a strong oxidizer.
Sodium peroxide is
hydrolyzedHydrolysis is a chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions, which may go on to participate in further reactions. It is the type of reaction that is used to break down certain polymers, especially those made by step-growth polymerization...
by water to form
sodium hydroxideSodium hydroxide , also known as lye and caustic soda, is a caustic metallic base. It is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents and as a drain cleaner. Worldwide production in 1998 was around...
plus
hydrogen peroxideHydrogen peroxide is a very pale blue liquid, slightly more viscous than water, that appears colorless in dilute solution. It is a weak acid, has strong oxidizing properties, and is a powerful bleaching agent. It is used as a disinfectant, antiseptic, oxidizer, and in rocketry as a propellant...
according to the reaction:
- Na2O2 + 2 H2O → 2 NaOH + H2O2
The hydrogen peroxide thus formed decomposes rapidly in the ensuing basic solution, producing water and oxygen.
Sodium peroxide, Na
2O
2, is the normal product when sodium is burned. It is a strong oxidizer.
Chemical Properties
Sodium peroxide is
hydrolyzedHydrolysis is a chemical reaction during which one or more water molecules are split into hydrogen and hydroxide ions, which may go on to participate in further reactions. It is the type of reaction that is used to break down certain polymers, especially those made by step-growth polymerization...
by water to form
sodium hydroxideSodium hydroxide , also known as lye and caustic soda, is a caustic metallic base. It is used in many industries, mostly as a strong chemical base in the manufacture of pulp and paper, textiles, drinking water, soaps and detergents and as a drain cleaner. Worldwide production in 1998 was around...
plus
hydrogen peroxideHydrogen peroxide is a very pale blue liquid, slightly more viscous than water, that appears colorless in dilute solution. It is a weak acid, has strong oxidizing properties, and is a powerful bleaching agent. It is used as a disinfectant, antiseptic, oxidizer, and in rocketry as a propellant...
according to the reaction:
- Na2O2 + 2 H2O → 2 NaOH + H2O2
The hydrogen peroxide thus formed decomposes rapidly in the ensuing basic solution, producing water and oxygen. The reaction is substantially exothermic and can set fire to combustible materials.
Sodium peroxide will also set fire to many organic liquids on contact (particularly
alcoholIn chemistry, an alcohol is any organic compound in which a hydroxyl group is bound to a carbon atom of an alkyl or substituted alkyl group. An important group of acohols is formed by the simple acyclic alcohols, the general formula for which is C
nH
2n+1OH...
s and glycols), and reacts violently with powdered metals and numerous other compounds after minimal initiation.
Structural Transitions
The hexagonal crystal structure of sodium peroxide was discovered by Tallman
et al. (1957). Upon heating, the structure undergoes a transition into a phase of unknown symmetry at 512 °C. With further heating above the 675 °C melting point, the compound decomposes, releasing O
2, before reaching a boiling point.
Preparation
Sodium peroxide can be synthesized by direct reaction with sodium and oxygen at 130–200 °C. Lower temperature (0–20 °C) synthesis can be achieved by passing O
2 over a dilute (0.1–5.0 mole percent)
sodium amalgamSodium amalgam, commonly denoted Na, is an amalgam, or alloy of mercury, with sodium metal. When metallic sodium is dissolved in mercury, it reacts exothermically to produce the intermetallic compound NaHg2, with enough heat to cause localised boiling of the mercury. This process is...
, thus oxidizing the sodium. It may also be produced by passing ozone gas over solid
sodium iodideSodium iodide is a white, crystalline salt with chemical formula NaI used in radiation detection, treatment of iodine deficiency, and as a reactant in the Finkelstein reaction.-Uses:Sodium iodide is commonly used to treat and prevent iodine deficiency....
inside a
platinumPlatinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is in Group 10 of the periodic table of elements...
or
palladiumPalladium is a chemical element with the chemical symbol Pd and an atomic number of 46. Palladium is a rare and lustrous silvery-white metal that was discovered in 1803 by William Hyde Wollaston, who named it after the asteroid Pallas, which in turn, was named after the epithet of the Greek...
tube. The ozone oxidizes the sodium to form sodium peroxide. The
iodineIodine , is a chemical element that has the symbol I and atomic number 53. Naturally-occurring iodine is a single isotope with 74 neutrons....
is freed into iodine crystals, which can be sublimed by mild heating. The platinum or palladium catalyzes the reaction and is not attacked by the sodium peroxide.
Uses
Given its strong oxidation properties, sodium peroxide is used to bleach wood pulp for the production of paper. It has also been used for the extraction of minerals from various ores. Sodium peroxide may go by the commercial names of
Solozone and
Flocool. In chemistry preparations, sodium peroxide is used as an oxidising agent. It is also used as an oxygen source by reacting it with carbon dioxide to produce oxygen and sodium carbonate; it is thus particularly useful in scuba gear, submarines, etc. See also
lithium peroxideLithium peroxide is a chemical compound. It decomposes above 195°C to give lithium oxide, Li2O:-Preparation:...
(similar use).
External links