Sodium ferrocyanide[1] | |
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Tetrasodium [hexacyanoferrate(II)] |
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Other names
Yellow prussiate of soda (YPS), Tetrasodium hexacyanoferrate, Gelbnatron, Ferrocyannatrium, sodium hexacyanoferrate(II) |
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Identifiers | |
CAS number | 13601-19-9 |
PubChem | 26129 |
EC number | 237-081-9 |
Properties | |
Molecular formula | Na4Fe(CN)6 |
Molar mass | 303.91 g/mol |
Appearance | Yellow crystals |
Density | 1.458 g/cm3 |
Melting point |
435 °C (decomposes) |
Solubility in water | 18 g/100 mL |
Structure | |
Crystal structure | monoclinic |
Hazards | |
S-phrases | S22 S24 S25 |
Related compounds | |
Other anions | Sodium ferricyanide (Red prussiate of soda) |
(verify) (what is: / ?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) |
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Infobox references |
Sodium ferrocyanide is the sodium salt of the coordination compound of formula [Fe(CN)6]4-. It is a yellow crystalline solid that is soluble in water and insoluble in alcohol. Despite the presence of the cyanide ligands, sodium ferrocyanide is not especially toxic (acceptable daily intake 0–0.025 mg/(kg body weight)[2]) because the cyanides are tightly bound to the metal. In its hydrous form, Na4Fe(CN)6·10H2O (sodium ferrocyanide decahydrate), it is sometimes known as yellow prussiate of soda. The yellow color is the color of ferrocyanide anion.
Sodium ferrocyanide is a chemical additive known as E 535. It is added to road and food grade salt as an anticaking agent.[2] When combined with iron, it converts to a deep blue pigment called Prussian blue.[3] In photography, it is used for bleaching, toning, and fixing. It is used as a stabilizer for the coating on welding rods. In the petroleum industry, it is used for removal of mercaptans.
Sodium ferrocyanide is produced industrially from hydrogen cyanide, ferrous chloride, and calcium hydroxide, the combination of which affords Ca2[Fe(CN)6].11H2O. A solution of this salt is then treated with sodium salts to precipitate the mixed calcium-sodium salt CaNa2[Fe(CN)6], which in turn is treated with sodium carbonate to give the tetrasodium salt.[4]
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