Barium ferrate (VI)

Structural formula
General
Surname	Barium ferrate (VI)
Molecular formula	BaFeO 4
Brief description	red-purple solid
External identifiers / databases
CAS number 13773-23-4 Wikidata Q413900
properties
Molar mass	257.17 g mol −1
Physical state	firmly
solubility	almost insoluble in water
safety instructions
GHS hazard labeling no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Barium ferrate (VI) is a chemical compound with the formula BaFeO ₄ . It contains iron in its highest oxidation level currently known, +6. Barium ferrate is isomorphic with barium sulfate (BaSO ₄ ) and contains the ferrate ion FeO ₄ ²⁻ , in which the iron is tetrahedrally surrounded by four oxygen atoms.

history

Barium ferrate was first produced and studied by Heinrich Rose in 1843 ; further research was carried out by J. de Mollins and L. Moeser in 1897 in 1871.

presentation

Barium ferrate

Ferrates are generally obtained by oxidizing an iron compound or elemental iron with a strong oxidizing agent. Thus, by annealing iron with potassium nitrate, potassium ferrate can be obtained, which after cooling can be dissolved in ice water by leaching. The reaction is not quantitative, iron oxides are also formed, which settle as insoluble residue at the bottom of the vessel. The ferrate must be precipitated immediately from the filtrate of this solution with barium chloride as barium ferrate, otherwise it will decompose quickly. The precipitate is washed first with water, then with aldehyde-free ethanol and then dried in a vacuum desiccator.

${\displaystyle \mathrm {Fe+2\ KNO_{3}\longrightarrow K_{2}FeO_{4}+N_{2}+O_{2}} }$

Representation of potassium ferrate from iron and potassium nitrate by glow

${\displaystyle \mathrm {K_{2}FeO_{4}+Ba(NO_{3})_{2}\longrightarrow BaFeO_{4}\downarrow +2\ KNO_{3}} }$

Precipitation of barium ferrate using barium nitrate

properties

Barium ferrate occurs as the monohydrate BaFeO ₄ · H ₂ O.

Like all ferrates, barium ferrate is a strong oxidizing agent which, for example, exceeds permanganates in terms of their oxidizing power ( normal potential for Fe ³⁺ / FeO ₄ ²⁻ at pH 0: 2.2 V; at pH 14: 0.55 V). In the acidic range, the ferrate ion reacts immediately with water, separating iron (III) oxide and oxygen .

Individual evidence

1. ↑ ^{a b} Jander Blasius, Inorganische Chemie 2, 16th edition, 2011. Page 314. ISBN 978-3-7776-2133-3 .
2. ↑ Physical characteristics, electrochemical behavior and stability of barium ferrate. doi : 10.1016 / j.electacta.2004.03.013 .
3. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.
4. ^ Longman A-level course in chemistry, 4th Edition, 2005. ISBN 9814105082 .
5. ↑ H. Rose: "About the composition of iron acid" in Pogg. Ann , 1843 , 59 , pp. 315-325. Full text .
6. ↑ J. de Mollins, in reports of the German chemical society , 1871 , 4 , pp. 626–627. Full text .
7. ↑ L. Moeser: "On the knowledge of the iron acid salts" in Journal für Praktische Chemie , 1897 , 56  (1), pp. 425–437. doi : 10.1002 / prac.18970560133 .
8. ↑ GW Thompson, LT Ockerman, JM Schreyer ". Preparation and Purification of Potassium Ferrate VI" in J. Am. Chem. Soc. , 1951 , 73  (3), pp. 1379-1381. doi : 10.1021 / ja01147a536 .
9. ^ JR Gump, WF Wagner, JM Schreyer: "Preparation and Analysis of Barium Ferrate (VI)" in Anal. Chem. , 1954 , 26  (12), p. 1957. doi : 10.1021 / ac60096a027 .
10. ↑ H. Firouzabadi, D. Mohajer, M. Entezari-moghaddam: "Barium Ferrate Monohydrate BaFeO ₄ · H ₂ O, A Versatile Reagent for the Oxidation of Organic Compounds under Aprotic Condition" in Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry , 1986 , 16  (6), pp. 723-731. doi : 10.1080 / 00397918608057745 .
11. ^ ^{A b} A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 102nd edition. Walter de Gruyter, Berlin 2007, ISBN 978-3-11-017770-1 , pp. 1646-1665.