Potassium Ferrocyanide Nitrate

Put 20 g. of potassium ferrocyanide in a 250-cc. Erlenmeyer flask, adding 30 cc. of water. Place the flask on the water bath and heat till the ferrocyanide dissolves. Add 35 cc. of nitric acid (sp. gr., 1.24) and continue heating until a test portion shows no blue color but a dark green precipitate when treated with ferrous sulfate. Let stand for a day or two and filter off the tarry impurities. Now neutralize with sodium carbonate, taking care that no excess is added. Warm and, when cool, add from one to two times the volume of alcohol (ethyl). Set the flask in a dry place for a day or two, after which the impurities (chiefly crystals of potassium nitrate) may be filtered off, and the nitro-prusside crystallized out. Sometimes two or three treatments with alcohol are necessary. In order to expedite the operation of evaporating down to crystallization, the solution may be evaporated by heating in a suction flask under reduced pressure. Quick crystallization increases the yield. The yield should be above 75 per cent. 

Sulphates, Copper, and Alkalies. — Boil for a few minutes a solution of 5 gm. of ferrous chloride in 10 cc. of water and 5 cc. of nitric acid (sp. gr. 1.3), dilute to 120 cc., add 20 cc. of ammonia water, and filter evaporate 50 cc. of the filtrate and ignite the residue. The weight of the latter should not exceed 0.001 gm. Slightly acidulate 20 cc. of the filtrate with hydrochloric acid and add barium nitrate solution. No change should appear. 20 cc. of the filtrate acidified with acetic acid should show no change upon addition of potassium ferrocyanide solution. 

Chlorides. — Deflagrate a mixture of 0.5 gm. of powdered potassium ferrocyanide and 1 gm. of potassium nitrate, by introducing small quantities at a time into a porcelain crucible heated to redness. Treat the residue with 20 cc. of water, filter, and to the filtrate add 3 cc. of nitric acid and silver nitrate solution. The liquid should not develop more than a slight opalescence. 

H. Stamm also measured the solubilities of the salts of the alkalies in liquid ammonia —potassium hydroxide, nitrate, sulphate, chromate, oxalate, perchlorate, persulphate, chloride, bromide, iodide, carbonate, and chlorate rubidium chloride, bromide, and sulphate esesium chloride, iodide, carbonate, and sulphate lithium chloride and sulphate sodium phosphate, phosphite, hypophosphite, fluoride, chloride, iodide, bromate, perchlorate, periodate, hyponitrire, nitrite, nitrate, azide, dithionate, chromate, carbonate, oxalate, benzoate, phtnalate, isophthalate ammonium, chloride, chlorate, bromide, iodide, perchlorate, sulphate, sulphite, chromate, molybdate, nitrate, dithionate, thiosulphate, persulphate, thiocyanate, phosphate, phosphite, hypophosphite, arsenate, arsenite, amidosulphonate, ferrocyanide, carbonate, benzoate, methionate, phenylacetate, picrate, salicylate, phenylpropionate, benzoldisulphonate, benzolsulphonate, phthalate, trimesmate, mellitate, aliphatic dicarboxylates, tartrate, fumarate, and maleinate and phenol. 

Experiment Prepare a solution of a ferrous salt by dissolving 2 grams of ferrous ammonium sulphate in 20 cc. of water, adding a little dilute sulphuric acid and a piece of iron wire. Test both this solution and a solution of a ferric salt (nitrate or chloride) with potassium ferrocyanide, potassium ferricyanide, and potassium sulphocyanate. Tabulate the results. These constitute the standard tests for ferrous and ferric salts. Write equation. 

In dilute solution ferric nitrate is hydrolysed, yielding colloidal ferric hydroxide and free nitric acid. Such solution gives no coloration with potassium ferrocyanide. In less dilute solutions, to which potassium ferrocyanide has already been added, the blue colour gradually intensifies owing to the continued re-formation of ferric nitrate, as the equilibrium represented by the equation... 

Natrosol is soluble in most 10% salt solutions, excluding sodium carbonate and sodium sulfate, and many 50% salt solutions with the exception of the following aluminum sulfate ammonium sulfate diammonium phosphate disodium phosphate ferric chloride magnesium sulfate potassium ferrocyanide sodium metaborate sodium nitrate sodium sulfite trisodium phosphate and zinc sulfate. Natrosol 150 is generally more tolerant of dissolved salts than is Natrosol 250. 

When the pale violet substance ferric nitrate, Fe(NOj)3-6H20, and the yellow substance potassium ferrocyanide, K4Fe(CN)6-4H20, are dissolved in water and the solutions are mixed, a precipitate with a brilliant blue color is formed. This precipitated substance is called Prussian blue. It is used as a pigment. Its formula is KFe2(CN)6-H20. 

COPPER NITRATE or COPPER(n) NITRATE (3251-23-8) A strong oxidizer. Violent reaction with reducing agents, combustible materials, acetic anhydride, ethers, potassium ferrocyanide, finely divided tin. The aqueous solution is a medium-strong acid. Incompatible with bases, acetylene, ammonia, aliphatic amines, aikanolamines, amides, alkylene oxides, cyanides, epichlorohydrin, esters, isocyanates, organic anhydrides, vinyl acetate. Attacks metals in the presence of moisture. 

Sodium diisobutyl dithiophosphate Sodium diisopropyl dithiophosphate Sodium di-(methylamyl) dithiophosphate Stearyl hydroxyethyl imidazoline flotation collector, zinc sulfide ore Sodium di-s-butyl dithiophosphate flotation depressant Acacia Calcium ferrocyanide Carboxymethylcellulose sodium Hydrofluoric acid Potassium ferricyanide Potassium ferrocyanide Sodium metabisulfite flotation depressant, copper ores Dicyandiamide Guanidine nitrate 2-Mercaptoethanol Phosphorus pentasulfide Quinolinic acid... 

Hildebrandt published several papers and a book on mercury compounds, on quicklime, ammonium nitrate, the composition of ammonia, the preparation of pure potassium ferrocyanide, on blood, nutrition, and animal heat, and on action at a distance in the restoration (Herstellung) of metals. ... 

Procedure. A drop of a 1 AT solution of potassium ferrocyanide is added to a drop of a cold saturated solution of zinc sulfate (or nitrate) and then a drop of 1 % sodium nitroprusside is added. White zinc ferrocyanide precipitates. A drop of the neutral test solution is introduced. The precipitate becomes red if sulfite is present. 

DEKTAL DEVELOPER KODAK FIXER KODAK SHORT STOP POTASSIUM ALUM POTASSIUM BICARBONATE POTASSIUM BICHROMATE POTASSIUM BORATE POTASSIUM BROMATE POTASSIUM BROMIDE POTASSIUM CARBONATE POTASSIUM CHROMATE POTASSIUM CHLORATE POTASSIUM CHLORIDE POTASSIUM CYANIDE POTASSIUM DICHROMATE POTASSIUM FERRICYANIDE POTASSIUM FERROCYANIDE POTASSIUM FLUORIDE POTASSIUM HYDROXIDE POTASSIUM NITRATE POTASSIUM PERBORATE POTASSIUM PERCHLORATE POTASSIUM PERMANGANATE. 10% POTASSIUM SULFATE PROPANE PROPANE GAS PLATING SOLUTIONS BRASS CADMIUM COPPER GOLD INDIUM LEAD NICKEL RHODIUM SILVER TIN ZINC... 

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