Sodium superoxide

Sodium superoxide
IUPAC name sodium(I) superoxide
Other names sodium superoxide
Identifiers
CAS number	12034-12-7
PubChem	61542
Properties
Molecular formula	NaO2
Molar mass	54.9886 g/mol
Appearance	Yellow crystalline solid
Density	2.2 g/cm3
Melting point	551.7 °C
Boiling point	Decomposes
Solubility in water	Decomposes
Basicity (pKb)	N/A
Hazards
EU classification	Corrosive
R-phrases	R35
S-phrases	S1/2, S26, S37/39, S45
NFPA 704	0 3 1 OX
Flash point	Non flammable
Related compounds
Other anions	sodium oxide sodium peroxide
Other cations	potassium superoxide
Y superoxide (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Sodium superoxide is the inorganic compound with the formula NaO₂. This yellow-orange solid is a salt of the superoxide anion. It is an intermediate in the oxidation of sodium by oxygen.

NaO₂ is prepared by treating sodium peroxide with oxygen at high pressures:^[1]

Na₂O₂ + O₂ → 2 NaO₂

It can also be prepared by careful oxygenation of a solution of sodium in ammonia:

Na + O₂ → NaO₂

The product is paramagnetic, as expected for a salt of the O₂⁻ anion. It hydrolyses readily to give a mixture of sodium hydroxide and hydrogen peroxide, oxygen may also be evolved.^[2]. It crystallizes in the NaCl motif.^{[citation needed]}

References

1. ^ Stephen E. Stephanou, Edgar J. Seyb Jr., Jacob Kleinberg "Sodium Superoxide" Inorganic Syntheses 1953; Vol. 4, 82-85.
2. ^ Sasol Encyclopaedia of Science and Technology , G.C. Gerrans, P. Hartmann-Petersen , p.243 "sodium oxides" , google books link