Potassium zinc ferrocyanide

Ferrocyan-kaUum, n. potassium ferrocyanide. -kupfer, n. cupric ferrocyanide. -natrium, n. sodium ferrocyanide. -silber, n. silver ferrocyanide. -verbindung, /. ferrocyanide. -wasserstoff, m., -wasserstoffsMure, /. ferro-cyanic acid, -zink, n. zinc ferrocyanide. -zinn, n. tin ferrocyanide. 

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. 

Alkali ferricyanides oxidize acid solutions of diethylaniline and other aromatic amines, as well as certain monoazo dyestuffs a change of color results and ferrocyanide is formed. This reversible redox reaction, proceeds very slowly and incompletely. However, if the ferrocyanide ions are removed as insoluble white zinc ferrocyanide, the oxidation proceeds rapidly. This acceleration is a result of raising the oxidation potential of ferricyanide ions through removal of ferrocyanide ions. The white zinc ferrocyanide is deeply tinted by adsorption of the colored quinoidal oxidation products of the amines, and thus affords a sensitive test for zinc. The test is especially useful in the presence of chromium and aluminum. It can also be used in other instances provided no other cations are present, which form colored precipitates with potassium ferrocyanide (Co+, Ni+, Fe+, Mn+ , Cu+ ). Traces of iron, which in practice are always to be reckoned with, do not interfere with the zinc test. Anions which oxidize the amines must be absent, e.g., permanganate, chromate, vanadate, persulfate, iodate. 

Other inorganic crystals studied by Mark and his collaborators, sometimes leading to complete structure determinations, include strontium chloride, zinc hydroxide, tin tetraiodide, potassium chlorate, potassium permanganage, and ammonium ferrocyanide. Minerals investigated by them include CaSO (anhydrite), BaSO (barite), PbSO, Fe2TiO[j (pseudobrookite), and three forms of Al2Si05 (cyanite, andalusite, and sillimanite). 

Broth Samples. Clarification with Zinc Acetate-Potassium Ferrocyanide. Transfer an aliquot of filtered broth expected to contain between 5 and 15 mg. of... 

Sbberellic acid to a 50-ml. volumetric flask, add 10.0 ml. of absolute alcohol, and lute to about 40 ml. with water. Add 2.0 ml. of zinc acetate solution, followed, after 2 minutes, by 2.0 ml. of potassium ferrocyanide solution. Adjust the contents of the flask to 50 ml. with water, mix, allow the flask to stand at room temperature for 5 minutes, and filter the contents through a Whatman No. 52 filter paper. Transfer 10.0-ml. aliquots of the filtrate to each of two 100-ml. volumetric flasks and add 8.0 ml. of absolute alcohol to each. Complete die determination as described above commencing with the addition of dilute hydrochloric acid (30%) to the first (sample) flask. 

If the solution is rendered alkaline with ammonia, boiled and any precipitate removed by filtration, the presence of zinc may be demonstrated by addition of potassium ferrocyanide, when the liquid becomes turbid. 

Zinc salts, in the presence of sodium acetate, yield a white precipitate with hydrogen sulfide. This precipitate, which is insoluble in acetic acid, is dissolved by 2.7 N hydrochloric acid. A similar precipitate is produced by ammonium sulfide TS in neutral or alkaline solutions. Solutions of zinc salts yield with potassium ferrocyanide TS (10%) a white precipitate that is insoluble in 2.7 N hydrochloric acid. 

Zinc potassium ferrocyanide, Zn3K2[Fe(CN)6]2, is obtained as an insoluble precipitate on adding an excess of potassium ferrocyanide to a zinc salt in aqueous solution.12... 

By adding sulphuric acid to a portion of the clear solution and estimating the excess of potassium ferrocyanide by titration with permanganate, the method may be made a convenient one for the estimation of zinc.13... 

The carbonates, sulphates, and borates are decomposed. The sulphides of the alkalies and alkaline earths are decomposed while the sulphides of arsenic, antimony, molybdenum, zinc, cadmium, tin, iron, lead, copper, mercury, and palladium are not attacked. Cobalt sulphate is not attacked, while the sulphates of the alkalies and alkaline earths are attacked and dissolved. Alkali tungstates, ammonium arsenite and arsenate, copper arsenite, ammonium magnesium arsenate, ammonium molybdate and vanadate, potassium cyanide and ferrocyanide are decomposed. Paraffin is not attacked shellac, gum arabic, gum tragacanth, copal, etc., are decomposed. Celluloid is slowly attacked. Silk paper, gun cotton, gelatin, parchment are dissolved. M. Meslans 22 has studied the esterification of alcohol by hydrofluoric acid. 

Hydroxyethyl cellulose has good tolerance for dissolved electrolytes, although it may be salted out of solution when mixed with certain salt solutions. For example, the following salt solutions will precipitate a 10% w/v solution of Cellosize WP-09 and a 2% w/v solution of Cellosize WP-4400 sodium carbonate 50% and saturated solutions of aluminum sulfate ammonium sulfate chromic sulfate disodium phosphate magnesium sulfate potassium ferrocyanide sodium sulfate sodium sulfite sodium thiosulfate and zinc sulfate. 

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. 

To address this concern, several organic and inorganic reagents were evaluated as precipitants for heavy metals in a 10-34-0 (N-P2O5-K2O) fluid fertilizer and WPA. Trisodium trithiocyanuric acid (TMT-15), sodium polythiocarbonate (Thio-Red II), and sodium trithiocarbonate (5% Na2 CS3) precipitated arsenic, cadmium, copper, mercury, lead, and zinc from 10-34-0. Ammonium cyanurate was ineffective in removing cadmium from 10-34-0. Thio-Red II and 5% Na2CS3 precipitated mercury, lead, cadmium, copper, and chromium from WPA. A water-insoluble starch xanthate adsorbed mercury, copper, and lead from 10-34-0 and WPA. Sodium sulfide, sodium polysulfide, and potassium ferrocyanide were tested as inorganic precipitants. The polysulfide was twice as effective as the sulfide alone, and concentrations of less than 10 ppm of arsenic, cadmium, mercury, and lead were achieved in 10-34-0. Ferrocyanide reduced the concentrations of cadmium and nickel to less than 10 ppm in WPA. 

A cyano group can be introduced using palladium and zinc cyanide, potassium cyanide or potassium ferrocyanide, the last having the significant advantage of low toxicity, and can be carried out with either a paUadium " or copper catalyst. Tri-n-butyltin cyanide can be used similarly, but a modification using catalytic tri- -butyltin chloride with potassium cyanide is much to be preferred. ... 

Materials Solutions of ferric chloride, of stannous chloride, of potassium ferrocyanide, of potassium ferricyanide, iron, zinc. 

Solutions of oxide of zinc are recognised by the following characters. Caustic alkalies produce a bulky white precipitate of hydrate, soluble in an excess of the alkali. The alkaline carbonates precipitate a bulky white carbonate of zinc, permanent when carbonate of soda or potash is employed, but soluble in excess of carbonate of ammonia. Sulphuretted hydrogen has no action if the solution be acid but if it be quite neutral forms a white precipitate of hydrated sulphuret of zinc, which is best formed by hydrosulphuret of ammonia. Ferrocyanide of potassium also causes a white precipitate. 

Potassium ferrocyanide reacts with both ferrous (Fe +) and ferric (Fe +) ions, producing several insoluble salts of different colors. The ferrous iron salt is white, while ferric iron produces a blue precipitate (Prussian blue). Other metals are also precipitated, mainly copper and zinc as well as, to a lesser extent, lead and tin. 

Zinc concentrations in wines range from 0.14 to 4 mg/1. Prolonged maceration of grape solids leads to an increase in zinc concentrations. The use of potassium ferrocyanide to treat ferric casse reduces a wine s zinc content (Table 4.3). 

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... 

Ferric ferrocyanide Zinc potassium chromate pigment, zinc white Carbon monoxide pigment dispersant leather PEG-32 castor oil PEG-75 castor oil PEG-160 castor oil... 

Moseley devised an apparatus which enabled the X-rays generated by firing electrons at a metallic target in a cathode ray tube to be diffracted by a crystal of potassium ferrocyanide and the resulting spectral lines to be recorded photographically. Moseley found that each element produced its own characteristic set of X-ray lines, and he commented that the method makes the analysis of X-rays as simple as any other branch of spectroscopy. In his first paper Moseley measured the frequencies of one of the characteristic lines in the X-ray spectra of the elements from calcium to zinc (with the exception of scandium). He found that the frequency of the lines was proportional to Q, where Q increased by a constant amount between consecutive elements when ordered according to the periodic table. Moseley continued ... 

The addition of potassium ferrocyanide to an acidic solution of zinc and a dilute solution of methyl violet gives a yellow color Idn. Limit ... 

The zinc may be detected by dissolving a small amount of the test material in dilute sulfuric acid followed by the addition of 2 % solution of potassium ferrocyanide white Zn2[Fe(CN)e] precipitates. However, if iron salts are present in the sample, the colorless zinc salt is tinted blue because of the concurrent production of iron ferrocyanide. Under such circumstances the blue product is treated with ammonia water and the suspension is filtered or centrifuged. The clear solution is acidified a white precipitate results. 

For the cupric ion any other ion in equivalent amount may be substituted to cause the precipitation. This tendency of the colloid to adsorb the potassium ferrocyanide is important in analytical chemistry. It is evident that potassium ferrocyanide cannot be titrated with cupric chloride because the end point will be reached before an equivalent amount of cupric ion has been added. A great many other precipitates behave similarly and herein lies the reason that zinc salts cannot be titrated accurately with potassium ferrocyanide or sodium sulfide. 

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