POTASSIUM SUPEROXIDE

Potassium superoxide
Potassium superoxide
General
Systematic name	Potassium dioxide
Other names	Potassium superoxide
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	corrosive
NFPA 704	nfpa_h3.png nfpa_f0_ox.png nfpa_r3.png
R/S statement	R: 8-14-34 S: 17-27-36/37/39
Supplementary data page
Structure and properties	''n'', εr, 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)

'Potassium superoxide' is the chemical compound with the formula KO₂. This rare salt of the superoxide ion is produced by burning molten potassium in pure oxygen. Potassium superoxide is used as an 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.

Contents

Structural trends in dioxygen compounds

References

External links

Structural trends in dioxygen compounds

The derivatives of dioxygen, O₂, have characteristic O-O distances that correlate with the bond order of the O-O bond.

Dioxygen compound	name	O-O distance in Å	O-O bond order
O2+	dioxygenyl cation	1.12	2.5
O2	dioxygen	1.21	2
O2-	superoxide	1.28	1.5[1]
O22-	peroxide	1.49	1

References

1. Abrahams, S. C.; Kalnajs, J. “The Crystal Structure of α-Potassium Superoxide” Acta Crystallographica (1955) volume 8, pages 503-506. DOI:10.1107/S0365110X55001540.

External links