Potassium superoxide

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Potassium superoxide
Image:Potassium superoxide.jpg
General
Systematic name	Potassium dioxide
Molecular formula	KO₂
Molar mass	71.10 g/mol
Appearance	yellow solid
CAS number	[12030-88-5]
Properties
Density and phase	2.14 g/cm³, solid
Solubility in water	Decomposes
Melting point	425 °C decomp.
Structure
Coordination geometry	?
Crystal structure	?
Hazards
MSDS	External MSDS
Main hazards	?
NFPA 704

Flash point	? °C
R/S statement	R: ? S: ?
Supplementary data page
Structure and properties	n, ε_r, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Other anions	Potassium oxide Potassium peroxide
Other cations	Sodium superoxide
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references

Potassium superoxide (symbol KO₂) is a superoxide of potassium. It is produced by burning molten potassium in pure oxygen. Potassium superoxide is used as a powerful oxidizing agent in industrial chemistry, as a CO₂ scrubber, H₂O dehumidifier and O₂ generator in rebreathers, spacecraft and spacesuit life support systems.

Important reactions:

4 KO₂ + 2 H₂O → 4 KOH + 3 O₂

2 KOH + CO₂ → K₂CO₃ + H₂O

K₂CO₃ + CO₂ + H₂O → 2 KHCO₃

The Russian Space Agency has had success using potassium superoxide in chemical oxygen generators for its spacesuits and Soyuz spacecraft. KO₂ has also been utilized in canisters for rebreathers for fire fighting and mine rescue work, but had limited use in scuba rebreathers because of the dangers of explosive reaction with water. The theoretical capacity of KO₂ is the absorption of 0.309 kg CO₂ per kg of absorbent while 0.38 kg O₂ are generated per kg of absorbent. The human body though will produce more CO₂ than oxygen absorbed, thus a device or absorbent specifically for CO₂ scrubbing may also be required.