Potassium Ferricyanide

Synonyms: red prussiate of potash, potassium hexacyanoferrate

Chemical formula: K3(Fe(CN)6)

International name: POTASSIUM FERRICYANIDE

CAS No.: 13746-66-2

Grade: import, pure, GOST 4206-75

Appearance: ruby crystals

Potassium ferricyanide (red prussiate of potash) K3[Fe(CN)6] is dark red rhombic crystals; water solution is yellowish-green; exposed to light, it is gradually decomposed forming K4[Fe(CN)6]. In alkaline medium, potassium ferricyanide is a strong oxidant (especially under heating). When heating with diluted sulfuric acid, it is decomposed releasing prussic acid, when exposed to concentrated H2SO4, carbon oxide is released.

Production

Potassium ferricyanide is produced by oxidation K4[Fe(CN)6] with chloride in muriate medium, bromine or other strong oxidant, e.g. potassium permanganate.

Application

Potassium ferricyanide (red prussiate of potash, potassium hexacyanoferrate) is used as follows:

• in photography, as a component of toning, bleaching, enhancing, reducing solutions in photography,
• as electrolyte in solion devices, a component of electrolytes in galvanoplastics, reagent for Fe2+, Li+, Sn2+ detection as well as a strong oxidant,
• in soil science, for gleization qualitative determination (ferrous iron salts), etc.