Main page (Russian) Search in database (English)

Properties of substance:

potassium superoxide

Group of substances:

inorganic

Physical appearance:

yellow tetragonal crystals

Empirical formula (Hill's system for organic substances):

KO2

Structural formula as text:

KO2

Molar/atomic mass: 71.1

Melting point (°C):

440

Decomposition temperature (°C):

702

Solubility (g/100 g of solvent):

ammonia liquid : 0.036 (-40°C) [Ref.]
cesium nitrate fused: soluble [Ref.]
dimethylsulfoxide: very slightly soluble [Ref.]
ethanol: reaction [Ref.]
potassium nitrate fused: soluble [Ref.]
rubidium nitrate fused: soluble [Ref.]
water: reaction [Ref.]

Hygroscopic:

yes

Interatomic distances and bond angles:

Interatomic distances (in pm): 271 (K-O) [crystals]
Interatomic distances (in pm): 292 (K-O) [crystals]
Interatomic distances (in pm): 128 (O-O) [crystals]

Numerical data:

Year of discovery: 1811

Density:

2.14 (20°C, g/cm3)

Reactions of synthesis:

  1. [Ref.1]
    K + O2 → KO2
  2. [Ref.1, Ref.2]
    K + O2 → KO2

Reactions:

  1. [Ref.1]
    2KO2 → K2O2 + O2
  2. [Ref.1]
    KO2 + O3 → KO3 + O2

Electrode potential:

HO2 + H+ + e- → H2O2, E = 1.495 V (water, 25°C)

Standard molar enthalpy (heat) of formation ΔfH0 (298.15 K, kJ/mol):

-280 (s)

Standard molar Gibbs energy of formation ΔfG0 (298.15 K, kJ/mol):

-209 (s)

Standard molar entropy S0 (298.15 K, J/(mol·K)):

117 (s)

Molar heat capacity at constant pressure Cp (298.15 K, J/(mol·K)):

77.5 (s)

Molar enthalpy (heat) of fusion ΔfusH (kJ/mol):

20

Neel temperature (K):

7

References:

  1. Алабышев А.Ф., Грачев К.Я., Зарецкий С.А., Лантратов М.Ф. Натрий и калий (получение, свойства и применение). - Л.: ГНТИХЛ, 1959. - pp. 283-285 [Russian]
  2. Вольнов И.И. Перекисные соединения щелочных металлов. - М.: Наука, 1980. - pp. 69-102 [Russian]
  3. Перекись водорода и перекисные соединения. - Под ред. Позина М.Е. - М.-Л.: ГНТИХЛ, 1951. - pp. 295-296 [Russian]
  4. Рабинович В.А., Хавин З.Я. Краткий химический справочник. - Л.: Химия, 1977. - pp. 69 [Russian]
  5. Успехи химии. - 1979. - Т.48, №11. - pp. 1970-1977 [Russian]
  6. Химическая энциклопедия. - Т. 3. - М.: Советская энциклопедия, 1992. - pp. 491 [Russian]

    What information do you need?




    © Collected Ruslan Anatolievich Kiper, burewestnik@mail.ru