Adverts

Open Access Articles- Top Results for Potassium superoxide

Potassium superoxide

Potassium superoxide
Unit cell of potassium superoxide
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Names

#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-

IUPAC name
Potassium dioxide
Other names
Potassium superoxide
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Identifiers#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-



12030-88-5 7pxY
ChemSpider 26237 7pxN
EC number 234-746-5
Jmol-3D images Image
PubChem Template:Chembox PubChem/format
RTECS number TT6053000
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Properties

#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-

KO2
Molar mass Lua error in Module:Math at line 495: attempt to index field 'ParserFunctions' (a nil value). g·mol−1
Appearance yellow solid
Density 2.14 g/cm3, solid
Melting point Script error: No such module "convert". (decomposes)
decomposes
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Structure

#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-

Crystal structure Body-centered cubic (O2)
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Thermochemistry

#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-

117 J·mol−1·K−1[1]
−283 kJ·mol−1[1]
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Hazards

#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-

Main hazards corrosive, oxidant
R-phrases 8-14-34
S-phrases 17-27-36/37/39
NFPA 704

Error: Must specify an image in the first line.

0
3
3
colspan=2 style="background:#f8eaba; border-top:2px solid transparent; border-bottom:2px solid transparent; text-align:center;" #REDIRECTmw:Help:Magic words#Other
This page is a soft redirect. Related compounds

#REDIRECTmw:Help:Magic words#Other
This page is a soft redirect.-

Other anions
Potassium oxide
Potassium peroxide
Other cations
Sodium superoxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
 14pxN verify (what is10pxY/10pxN?)
Infobox references

Potassium superoxide is the inorganic compound with the formula KO2. It is a yellow paramagnetic solid that decomposes in moist air. It is a rare example of a stable salt of the superoxide ion. Potassium superoxide is used as a CO2 scrubber, H2O dehumidifier and O2 generator in rebreathers, spacecraft, submarines and spacesuit life support systems.

Production and reactions

Potassium superoxide is produced by burning molten potassium in an atmosphere of oxygen.[2]

K + O2 → KO2

The salt consists of K+ and O2 ions, linked by ionic bonds. The O-O distance is 1.28 Å.[3]

Reactivity

Hydrolysis gives oxygen gas and base:

4 KO2 + 2 H2O → 4 KOH + 3 O2

Its degradation by carbon dioxide affords carbonates:

4 KOH + 2 CO2 → 2 K2CO3 + 2 H2O

Combinations of these two reaction occur as well:

4 KO2 + 2 CO2 → 2 K2CO3 + 3 O2
4 KO2 + 4 CO2 + 2 H2O → 4 KHCO3 + 3 O2

Potassium superoxide finds only niche uses as a laboratory reagent. Because it reacts with water, KO2 is often studied in organic solvents. Since the salt is poorly soluble in nonpolar solvents, crown ethers are typically used. The tetraethylammonium salt is also known. Representative reactions of these salts involve the use of superoxide as a nucleophile, e.g., in the conversion of alkyl bromides to alcohols and acyl chlorides into diacyl peroxides.[4]

Applications

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 its dangerously explosive reaction with water. The theoretical capacity of KO2 is the absorption of 0.618 kg CO2 per kg of absorbent while 0.380 kg O2 are generated per kg of absorbent. For one KO2 molecule, it's one CO2 molecule but only 0.75 oxygen molecules. The human body though will produce less CO2 molecules than oxygen molecules needed because oxidation of food also needs oxygen to produce water and urea.

Hazards

Potassium superoxide is a potent oxidizer, and can produce explosive reactions when combined with a variety of substances, including water, acids, organics, or powdered graphite. Even dry superoxide can produce an impact-sensitive explosive compound when combined with organic oils such as kerosene.[5] In 1999 at Oak Ridge National Laboratory, cleanup of potassium oxides from a NaK metal leak produced an impact-sensitive explosion while saturated with mineral oil.[6]

References

  1. 1.0 1.1 Zumdahl, Steven S. (2009). Chemical Principles 6th Ed. Houghton Mifflin Company. p. A22. ISBN 0-618-94690-X. 
  2. Harald Jakob, Stefan Leininger, Thomas Lehmann, Sylvia Jacobi, Sven Gutewort "Peroxo Compounds, Inorganic" Ullmann's Encyclopedia of Industrial Chemistry, 2007, Wiley-VCH, Weinheim. doi:10.1002/14356007.a19_177.pub2
  3. Abrahams, S. C.; Kalnajs, J. (1955). "The Crystal Structure of α-Potassium Superoxide". Acta Crystallographica 8: 503–506. doi:10.1107/S0365110X55001540. 
  4. Roy A. Johnson, Javier Adrio, María Ribagorda "Potassium Superoxide" e-EROS Encyclopedia of Reagents for Organic Synthesis, 2001 John Wiley & Sons. doi:10.1002/047084289X.rp250.pub2
  5. Aerojet Nuclear Company (1975). "An Explosives Hazards Analysis of the Eutectic Solution of NaK and KO2". Idaho National Engineering Laboratory. 
  6. "Y-12 NaK Accident Investigation". U.S. Department of Energy. February 2000. Archived from the original on 2010-05-28.