Potassium bismuthate

From Sciencemadness Wiki
Jump to: navigation, search
Potassium bismuthate
IUPAC name
Potassium bismuthate
Other names
Potassium bismuth oxide
Potassium bismuth trioxide
Molar mass 296.077 g/mol
Appearance Reddish or brown-reddish powdered solid
Odor Odorless
Vapor pressure ~0 mmHg
-683 kJ/mol[1]
Flash point Non-flammable
Related compounds
Related compounds
Sodium bismuthate
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Potassium bismuthate is an inorganic chemical compound, a strong oxidizer with chemical formula KBiO3.

Like its sodium counterpart, potassium bismuthate is contaminated with side products from the synthesis as well as decomposition.



Potassium bismuthate reacts with haloacids to will release their respective halogens. For example, reaction with hydrochloric acid will produce chlorine gas:

KBiO3 + 6 HCl → KCl + BiCl3 + Cl2

This reaction is similar to the reaction between potassium permanganate with HCl.

Addition of hydrogen peroxide will cause it to decompose and release oxygen.


Potassium bismuthate is a reddish or brown-reddish solid, insoluble in cold water and decomposes in hot water.


Potassium bismuthate is sold by some chemical suppliers, albeit it's less available than sodium bismuthate. Usually the product is ~90% pure.[2]


Can be prepared by bubbling chlorine gas through a hot suspension of potassium hydroxide and bismuth trioxide.[3]

Bi2O3 + 6 KOH + 2 Cl2 → 2 KBiO3 + 4 KCl + 3 H2O

Fusing potassium superoxide and bismuth trioxide at high temperatures and pressure will yield potassium bismuthate.[4]

2 KO2 + Bi2O3 → 2 KBiO3 + ½ O2

Potassium oxide can also be used.[5]

Stirring a mixture of sodium bismuthate with potassium hydroxide for 6 hours at 250 °C will produce KBiO3.[6]

The recommended literature preparation for potassium bismuthate is the oxidation of bismuth(III) oxide with a large excess of bromine in boiling 50% potassium hydroxide. The violet solid is suspended in water and decanted, during which time the color changes to red. The solid is dried over sulfuric acid and has the composition of KBiO3 x 1/3 H2O.[7]


  • Oxidizing agent
  • Make permangante
  • Compound collecting



Potassium bismuthate is an irritant if inhaled. Continued absorption of KBiO3 into body causes permanent kidney damage.


In closed plastic or glass bottles, away from moisture and acids.


Can be neutralized by exposure to hot water or hydrogen peroxide and the bismuth recycled.


  1. Kasenov; Zhambekov; Kasenova; Russian Journal of Physical Chemistry; vol. 71; nb. 6; (1997); p. 1024 - 1026
  2. https://mateck.com/potassium-bismuthate.html
  3. Deichler, C.; Zeitschrift fur anorganische Chemie; vol. 20; (1899); p. 98-102
  4. Baranov; Kim; Kim; Kang; Park; Pshirkov; Antipov; Physica. C, Superconductivity; vol. 357-360; nb. SUPPL. 2; (2001); p. 414 - 417
  5. Khasanova; Yoshida; Yamamoto; Tajima; Physica. C, Superconductivity; vol. 356; nb. 1-2; (2001); p. 12 - 22
  6. Saiduzzaman, Md; Yoshida, Hikaru; Takei, Takahiro; Yanagida, Sayaka; Kumada, Nobuhiro; Nagao, Masanori; Yamane, Hisanori; Azuma, Masaki; Rubel, Mirza H. K.; Moriyoshi, Chikako; Kuroiwa, Yoshihiro; Inorganic Chemistry; vol. 58; nb. 18; (2019); p. 11997 - 12001
  7. Scholder, R. and Stobbe, H., Z. Anorg. Allg. Chem. 1941, 247: 392-414. https://doi.org/10.1002/zaac.19412470404. For an english translation of this preparation see G. Brauer, Handbook of preparative inorganic chemistry, Second edition 1963, p. 628-629

Sciencemadness library

Relevant Sciencemadness threads