Ferric ferrocyanide

Ferric chloride solution is then added to com ert the sodium ferrocyanide to the deep blue ferric ferrocyanide (or Prussian Blue), dilute sulphuric acid being also added to dissolve any ferrous and ferric hydroxides present in the other-... 

Upon boiling the alkaline ferrous salt solution, some ferric ions are inevitably produced by the action of the air upon the addition of dilute siilphurio acid, thus dissolving the ferrous and ferric hydroxides, the ferrocyanides reacts with the ferric salt producing ferric ferrocyanide (Prussian blue) ... 

Water-soluble crystal modifiers such as yellow pmssiate of soda (YPS) (sodium ferrocyanide decahydrate) or ferric ammonium citrate may also be added to some types of salt as anticaking agents. Both are approved by the U.S. Food and Dmg Administration for use in food-grade salt. YPS and Pmssian Blue (ferric ferrocyanide), are most commonly added to rock salt used for wintertime highway deicing. Concentrations of YPS and Pmssian Blue in deicing salt vary, typically in the range of 20—100 ppm. 

Ferric ammonium ferrocyanide—The blue pigment obtained by oxidising under acidic conditions with sodium dichromate the acid-digested precipitate resulting from mixing solutions of ferrous sulfate and sodium ferrocyanide ia the presence of ammonium sulfate. The oxidized product is filtered, washed, and dried. The pigment consists principally of ferric ammonium ferrocyanide with small amounts of ferric ferrocyanide and ferric sodium ferrocyanide. 

Ferric ferrocyanide—Cl Pigment Blue 27, Cl No. 77510. The color additive ferric ferrocyanide is a ferric hexacyanoferrate is a pigment characterized by the stmctural formula Fe4[Fe(CN)g]2ArH20, which may contain small amounts of ferric sodium ferrocyanide and ferric potassium ferrocyanide. ... 

If the solution is acidified and aUtde ferric sulfate added, ferric ferrocyanide [14038-43-8], Fe4[Fe(CN)g]2, is produced. This salt has a characteristic deep blue color, and the reaction may be used to test for the cyanide. 

Ferrifeiro-cyanid, n. ferric ferrocyanide (Prussian blue), -jodid, n. ferroeoferric iodide, -oxyd, n. ferroeoferric oxide, iron(II,III) oxide. 

Ferrocyan, n. ferrocyanogen. -eisen, n. ferric ferrocyanide (Prussian blue). 

Prussian blue (PB ferric ferrocyanide, or iron(III) hexacyanoferrate(II)) was first made by Diesbach in Berlin in 1704.88 It is extensively used as a pigment in the formulation of paints, lacquers, and printing inks.89,90 Since the first report91 in 1978 of the electrochemistry of PB films, numerous studies concerning the electrochemistry of PB and related analogs have been made,92 with proposed applications in electrochromism1 and electrochemical sensing and catalysis 93... 

The fact that Prussian blue is indeed ferric ferrocyanide (Fe4in[Fen(CN)6]3) with iron(III) atom coordinated to nitrogen and iron(II) atom coordinated to carbon has been established by spectroscopic investigations [4], Prussian blue can be synthesized chemically by the mixing of ferric (ferrous) and hexacyanoferrate ions with different oxidation state of iron atoms either Fe3+ + [Fen(CN)6]4 or Fe2+ + [Fem(CN)6]3. After mixing, an immediate formation of the dark blue colloid is observed. However, the mixed solutions of ferric (ferrous) and hexacyanoferrate ions with the same oxidation state of iron atoms are apparently stable. 

Ferric citrate, molecular formula, 6 638t Ferric ethoxide, 14 533 Ferric ethylenediaminetetraacetic acid (ferric EDTA), 19 261 Ferric ferrocyanide, 8 186 22 810 pigment used in makeups, 7 836t Ferrichromes, 14 557 Ferric ion, acrylamide stabilizer, 1 289 Ferric nitrate bright pickle, 15 375 Ferric oxide... 

The depression of pyrite by cyanide has been considered from the electrochemical viewpoint, the formation of ferric ferrocyanide in the surface of pyrite which was perhaps responsible for cyanide depression was proposed by Ball and Richard (1976) to occur by the following electrochemical reaction. 

Prussian blue (inorgchem) Fe4 Fe(CN)6 3 Ferric ferrocyanide, used as a blue pigment and in the removal of hydrogen sulfide from gases. prash an blu j prussic acid See hydrocyanic acid. pras ik as ad ... 

Such cyanide complexes are also known for several other metals. All the fer-rocyanide complexes may be considered as the salts of ferrocyanic acid H4Fe(CN)e and ferricyanide complexes are that of ferricyanic acid, H3Fe(CN)e. The iron-cyanide complexes of alkali and alkaline-earth metals are water soluble. These metals form yellow and ruby-red salts with ferro-cyanide and ferricyanide complex anions, respectively. A few of the hexa-cyanoferrate salts have found major commercial applications. Probably, the most important among them is ferric ferrocyanide, FeFe(CN)e, also known as Prussian blue. The names, formulas and the CAS registry numbers of some hexacyanoferrate complexes are given below. Prussian blue and a few other important complexes of this broad class of substances are noted briefly in the following sections ... 

Ferric ferrocyanide [tetrairon(III) tris(hexakiscyanoferrate)(Prussian blue) Fe "4[Fe(CN)6]3 [14038-43-8]... 

Prussian blue or ferric ferrocyanide or iron(lll) hexakis(cyanoferrate(3—)) has the formula Fe4[Fe(CN)6]3. There are several commercial applications. It is used as pigment for paints, inks, typewriter ribbons, alkyd resins, enamels. 

The former of these is a ferric ferrocyanide, and the latter a ferrous ferricyanide. Both are in powder or masses of deep turquoise blue with reddish reflection the lighter and more spongy forms are the more highly valued. 

Fe4(Fe(CN)6)3 (c). Berthelot27 measured the heat of reaction of aqueous ferrocyanic acid with ferric hydroxide to be 76.6, and the heat of reaction of aqueous KCN with aqueous ferrous and ferric sulfates to be 225.0 whence, for ferric ferrocyanide, Qf=— 322.5 and —312. 

These pigments are manufactured by treating ferrous sulfate (FeS04) solutions (sometimes in the presence of ammonium sulfate) with sodium ferrocyanide, giving a white ferrous ferrocyanide, which is then oxidized to ferric ferrocyanide, Fe4[Fe(CN)6], or to Fe(NH4)[Tc(CN)6 by different reagents such as potassium chlorate, bleaching powder, and potassium dichromate. The colloidal pigment is washed and allowed to settle to enhance separation, since filtration of the colloidal solid is difficult. 

Iron blues, or cyanide iron blues, are complex ferriferrocyanide, generally with ammonium, potassium, or sodium cations. They are most commonly produced by a two-step process. First, ammonium, potassium, or sodium ferrocyanide, M4[Fe(CN)6], is reacted with ferrous sulfate, FeS04, to yield M2Fe[Fe(CN)]6. The latter is digested with hot sulfuric acid and oxidized with sodium chlorate or sodium bichromate to yield the ferric ferrocyanide M(Fe[Fe(CN)6]. ... 

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