Sodium superoxide is the

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 chemis ...

with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwe ...

Na O₂. This yellow-orange solid is a salt of the

superoxide In chemistry, a superoxide is a compound that contains the superoxide ion, which has the chemical formula . The systematic name of the anion is dioxide(1−). The reactive oxygen ion superoxide is particularly important as the product of t ...

anion. It is an intermediate in the oxidation of sodium by oxygen.

Preparation

NaO₂ is prepared by treating

sodium peroxide Sodium peroxide is an inorganic compound with the formula Na2O2. This yellowish solid is the product of sodium ignited in excess oxygen. It is a strong base. This metal peroxide exists in several hydrates and peroxyhydrates including Na2O2·2H2O ...

with

oxygen Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements ...

at high pressures: :Na₂O₂ + O₂ → 2 NaO₂ It can also be prepared by careful oxygenation of a solution of sodium in ammonia: :Na(in NH₃) + O₂ → NaO₂ It is also produced, along with

, when sodium is stored under inappropriate conditions (e.g. in dirty or partially halogenated solvents).

Properties

The product is

paramagnetic Paramagnetism is a form of magnetism whereby some materials are weakly attracted by an externally applied magnetic field, and form internal, induced magnetic fields in the direction of the applied magnetic field. In contrast with this behavior, ...

, as expected for a salt of the

anion An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by conve ...

. It hydrolyses readily to give a mixture of sodium hydroxide, oxygen and hydrogen peroxide.Sasol Encyclopaedia of Science and Technology , G.C. Gerrans, P. Hartmann-Petersen , p.243 "sodium oxides"
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/ref> It crystallizes in the NaCl motif.

References

Superoxides Sodium compounds Photographic chemicals Oxidizing agents {{inorganic-compound-stub