Calcium hexacyanoferrate

Calcium hexacyanoferrate (II) is produced by mixing liquid hydrogen cyanide with an aqueous solution of ferrous chloride and milk of lime. The resulting solution is filtered and evaporated to crystallise the hydrated calcium salt [31.9]. 

Calcium hexacyanoferrate is usually converted into either the sodium and potassium salts, or into the hexacyanoferrates (III) (otherwise known as ferricyanides, [Fe(CN)6] ). It is used in the production of blue pigments and salt (as an anti-caking agent). 

---

Calcium hexacyanoferrate (II) (IIH2O) [ 13821 -08-4] M 490.3. Recrystd three times from conductivity H2O and air dried to constant weight over partially dehydrated salt. [Trans Faraday Soc 45 855 1949.] Alternatively the Ca salt can be purified by pptn with absolute EtOH in the cold (to avoid oxidation) from an air-free saturated aqueous soln. The pure lemon yellow crystals are centrifuged, dried in a vacuum desiccator first over dry charcoal for 24h, then over partly dehydrated salt and stored in a dark glass stoppered bottle. No deterioration occurred after 18 months. No trace of Na, K or NH4 ions could be detected in the salt from the residue after decomposition of the salt with cone H2SO4. Analyses indicate 1 Imols of H2O per mol of salt. The solubility in H2O is 36.45g (24.9 ) and 64.7g (44.7 ) per lOOg of solution. [J Chem Soc 50 1926.]... 

Sodium or potassium hexacyanoferrate(II) or mixtures of these salts are used in most cases. When the pure sodium salt or a calcium hexacyanoferrate(II) solution is used, the pigment properties are obtained by adding a potassium or ammonium salt during the precipitation of the white paste product or prior to the oxidation stage. The iron(II) salt used is crystalline iron(II) sulfate or iron(II) chloride solution. 

Synonyms Calcium hexacyanoferrate Yellow prussiate of calcium Yellow prussiate of lime... 

Heating with the following solids, their fusions, or vapours (a) oxides, peroxides, hydroxides, nitrates, nitrites, sulphides, cyanides, hexacyano-ferrate(III), and hexacyanoferrate(II) of the alkali and alkaline-earth metals (except oxides and hydroxides of calcium and strontium) (b) molten lead, silver, copper, zinc, bismuth, tin, or gold, or mixtures which form these metals upon reduction (c) phosphorus, arsenic, antimony, or silicon, or mixtures which form these elements upon reduction, particularly phosphates, arsenates,... 

Crucibles fitted with permanent porous plates are cleaned by shaking out as much of the solid as possible, and then dissolving out the remainder of the solid with a suitable solvent. A hot 0.1 M solution of the tetrasodium salt of the ethylenediaminetetra-acetic acid is an excellent solvent for many of the precipitates [except metallic sulphides and hexacyanoferrates(III)] encountered in analysis. These include barium sulphate, calcium oxalate, calcium phosphate, calcium oxide, lead carbonate, lead iodate, lead oxalate, and ammonium magnesium phosphate. The crucible may either be completely immersed in the hot reagent or the latter may be drawn by suction through the crucible. 

Lead(II) azide Lead chromate Lead dioxide Calcium stearate, copper, zinc, brass, carbon disulfide Iron hexacyanoferrate(4-) Aluminum carbide, hydrogen peroxide, hydrogen sulfide, hydroxylamine, ni-troalkanes, nitrogen compounds, nonmetal halides, peroxoformic acid, phosphorus, phosphorus trichloride, potassium, sulfur, sulfur dioxide, sulfides,... 

Barium Halocarbons, 0200 Barium peroxide, 0216 l,2-Bis(azidocarbonyl)cyclopropane, 1835 Calcium hypochlorite, 3924 Chromium trioxide Potassium hexacyanoferrate(3—), 4242 Diazidodimethylsilane, 0918... 

Potassium hexacyanoferrate(II) or sodium hexacyanoferrate(II) or mixtures of these salts are usually used. When the pure sodium salt or a calcium hexacyanofer-... 

Ammonium hexacyanoferrate(II), 2572 f Arsine, 0100 Azido-2-butyne, 1469 3-Azidopropyne, 1111 cis-Azobenzene, 3478 Azoxybenzene, 3479 Barium azide, 0214 Benzenediazonium nitrate, 2268 Benzotriazole, 2262 Borane, 0135 Bromine azide, 0256 f 3-Bromopropyne, 1087 f 1,2-Butadiene, 1475 f 1,3-Butadiene, 1476 f Buten-3-yne, 1419 f 1-Butyne, 1477 f 2-Butyne, 1478 Cadmium azide, 3951 Cadmium cyanide, 0585 Cadmium fulminate, 0586 Cadmium nitride, 3954 Calcium azide, 3930 t Carbon disulfide, 0557 Chlorine dioxide, 4036 Chloroacetylene, 0648... 

Fe3+ can be quantitatively removed from sour wine with [Fe(CN)6]4, a usual procedure to remove iron ions from wine.371 Concentrated alkali carbonate solutions will precipitate the Fe2+ of Iron Blue as FeC03, so that they destroy the entire pigment by precipitating Fe3+ as Fe(OH)3 (due to alkalinity) and the hexacyanoferrate(II) salt [Fe(CN)6]4 372 Calcium carbonate solutions, however, would not be sufficient due to their marginal saturation solubility. Besides that, Kohn examined the supportive effect of most of the organic ligands to disperse Iron Blue.373... 

The formula for potassium arsenate is K3As04. The formula for potassium ferrocyanide, systematically called potassium hexacyanoferrate(II), is K4Fe(CN)g. Write the formulas for (a) calcium arsenate ib) iron(III) arsenate ... 

Basic copper(ll) carbonate Cobalt(ll) stannate Cobalt(ll)-doped alumina glass Calcium copper(ll) silicate Sulfur radical anions in a sodium aluminosilicate matrix Barium manganate(VII) sulfete Copper(ll) phthalocyanine Basic oopper(ll) sulfete Iron(lll) hexacyanoferrate(ll) Cobalt(ll) silicate Basic copper(ll)... 

Potassium Ferricyanide Potassium Hexacyanoferrate (III) Lead Sulfamate Calcium Bisulfite... 

Eastman 910 Potassium Ferricyanide Potassium Hexacyanoferrate (III) Calcium Bisulfite Calcium Nitrite Ammonium Fluoroborate Limonene Aluminum Acetate Potassium Ferrocyanide 2-Aminobutane sec-Butylamine Benzyl Acetate Phenylmethylacetate Ferrous Nitrate Iron (II) Nitrate... 

Solutions of the following salts are usually 0.5 M with respect to the hydrated salt ammonium thiocyanate, copper sulphate, iron(IIl) chloride, iron(II) sulphate, potassium iodide, potassium thiocyanate. Solutions of the following salts are usually 0.25 M barium chloride, calcium chloride, lead acetate, potassium chromate, potassium hexacyanoferrate(II), tin(II) chloride (with few pieces of Sn to stop aerial oxidation), zinc nitrate. 

---