Ammonium ferrocyanide hydrate

High resolution NMR study of ammonium ferrocyanide hydrate AFC)... 

Ferric ammonium ferrocyanide, FeNH4[Fe(CN)6], results when potassium ferrocyanide is heated with a solution of hydroxylamine hydrochloride. It is a deep blue insoluble powder.7 The hydrated salt FeNH4[Fe(CN)6].H20 is known as Monthiers9 blue,8 having been obtained by Monthier as the result of oxidising the white precipitate thrown down by the action of potassium ferrocyanide upon ammoniacal ferrous chloride solution. It may also be prepared by dissolving iron wire in a solution containing ammonia, ammonium chloride, and... 

For this the easiest method is to use potassium ferrocyanide and sponge or spray it with a dilute solution of iron sulphate or use copper sulphate and sponge or spray with ammonium hydrate. If we use acetate of cobalt—then this when heated gives a very similar result. 

Citrates.—Ferric Citrate—Ferri citras (XT. S.)—(Fea)(C H60T)a- -6Aq—489.8-1-108—is in garnet-colored scales, obtained by dissolving ferric hydrate in solution of citric acid, and evaporating the solution at about C0° (140° F.). It loses 3 Aq at 120° (248° F.), and the remainder at 150° (302° F.). If a small quantity of ammonium hydroxid be added, before the evaporation, the product consists of the modified citrate = ferri et ammonii citras (XT. S.), which only reacts with potassium ferrocyanid after addition of HCl. 

Analytical Characters.—Fbrbous—Are acid colorless when anhydrous pale green when hydrated oxidized by air to basic ferric compounds. (1.) Potash greenish-white ppt. insoluble in excess changing to green or brown in air. (2.) Ammonium hy-droxid greenish ppt. soluble in excess not formed in presence of ammoniacal salts. (3.) Ammonium sulfhydrate black ppt. insoluble in excess soluble in acids. (4.) Potassium ferrocyanid in absence of ferric salts) white ppt. turning blue in air. (5.) Potassium ferricyanid blue ppt. soluble in KHO insoluble in HCl. 

An inorganic molecule that contains several atoms, including one or more metal atoms, is called an inorganic complex or coordination compound. An example is nickel tetracarbonyl, Ni(CO)4. An inorganic complex with an electric charge is called a complex ion. Familiar examples of complex ions are the ferrocyanide ion, Fe(CN)e - the ferricyanide ion, Fe(CN)e the hydrated aluminum ion, A1(H20)6, and the deep blue cupric ammonia complex ion, Cu(NH3)4 +, which is formed by adding ammonium hydroxide to a solution of cupric salt. Complex ions are important in the methods of separation used in qualitative and quantitative chemical analysis and in various industrial processes. 

Copper sulphate and ammonium hydrate produce a blue solution also potassium ferrocyanide and weak solution of iron sulphate also ferrocyanide of jjotassium and ferrous sulphate (protosulphate of iron)—the last named being a deep blue. 

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