Ammonium arsenates

AMMO 2.5 EC , cypermetlu-in, 13 Ammonia, 13 Ammonium acetate, 13 Ammonium arsenate, 13 Ammonium benzoate, 13 Ammonium bicarbonate, 13 Ammonium bifluoride, 14 Ammonium bisulfite, 14 Ammonium carbamate, 14 Ammonium carbonate, 14 Ammonium chloride, 14 Ammonium chlorplatmate, 14 Ammonium clu omate, 14 Ammonium citrate, 14 Ammonium diclu omate, 14 Ammonium fluoride, 14 Ammonium fomiate, 15 Ammonium hexafluorosilicate, 15 Ammonium hydroxide, 15 Ammonium metavanadate, 15 Ammonium molybdate, 15 Ammonium nitrate, 15 Ammonium oxalate, 15 Ammonium perfluorooctanoate, 15 Ammonium persulfate, 15 Ammonium phosphate, 15 Ammonium picrate, 16 Ammonium salicylate, 16... 

Wilson and Dickenson observed no exchange, over a period of three hours at 100 °C, between arsenate and arsenite ions in media ranging from aqueous acid to aqueous alkali. Martin et al have found similar results for the exchange between arsenate and thioarsenite ions in aqueous media. However, in liquid ammonia exchange occurred between ammonium arsenate and arsenic trisulphide. The isotopic method was used -... 

Sowinski and Suffet 297) have used GC/MS to detect boron hydrides at trace levels, whereas Blum and Richter (298) have used capillary columns in the combined GC/MS of a series of phenylboronate derivatives. There have also been recent applications of GC/MS to the TMS derivatives of inorganic anions (299). The TMS derivatives of ammonium arsenates. 

The determination of ammonium, arsenic, thiosulfate, allyl alcohol, and iodide has been achieved with a bromine redox mediator. Tomcik etal. [156] employ interdigitated microelectrodes at which bromine is generated at one set of electrodes and collected at a second set of electrodes. The reaction of the bromine with the analytes allows quantitative determination down to a micromolar level. 

In 1869 Bettendorff recorded 1 the formation of a voluminous brown precipitate when stannous chloride was added to a solution of arsenious oxide, or of magnesium ammonium arsenate, in hydrochloric acid. The precipitate proved to be arsenic (96 to 99 per cent.) with traces of tin which were irremovable. The speed of precipitation depends upon the amount of arsenic present and the temperature. With solutions containing little arsenic, Bettendorff observed, on warming, a yellow colour before the precipitate appeared, but he was unable to prove that the colour was due to arsenic. The reaction involved may be represented thus—... 

A crystalline ammonium hexafluoarsenate has not been obtained. A mixture of ammonium arsenate and hydrofluoric acid on evaporation yields a gum-like mass. Arsenious oxide dissolves in a boiling solution of ammonium fluoride, but on cooling the arsenious oxide separates from the solution.3... 

The following values for the heats of neutralisation at 15° C. of arsenic acid by aqueous ammonia, and for the heats of dissolution of the ammonium arsenates, have been obtained.2 The solutions of arsenic acid for the determination of the former contained J mole of H3As04 per litre, and those of ammonia were of such concentrations that 1 volume of the acid was neutralised by an equal volume of the base. 

Barium Arsenates.—Barium orthoarsenate, Ba3(As04)2, is formed as large colourless plates when a mixture of barium oxide, alkali chloride and alkali hydrogen orthoarsenate is fused and allowed to cool.6 It is also said to be formed7 by the action of ammonia on an aqueous solution of barium hydrogen arsenate the product, however, varies in composition, barium ammonium arsenate sometimes being formed and... 

The solubility in water of magnesium ammonium arsenate is as follows (expressed in grams of MgXH4As04.6H20 per 100 grams of solution) 1... 

When mercuric oxide is treated with aqueous arsenic acid, the solid phase separates into two layers, one of which is mercuric oxide and the other a basic mercuric arsenate of composition 3Hg0.Hg3(As04)2. When ammonium arsenate solution acts on mercuric oxide, a product of composition Hg2NH2As04 is obtained.6... 

The magnesium ammonium arsenate may also be weighed as such with accurate results. The precipitated mixture should be filtered after cooling for about 2 hours at 0° to 5° C., washed with alcohol and ether, dried in a vacuum at room temperature, and weighed as MgNH4As04. 6H20. This process is suitable for semimicro-determinations.4... 

The pyro-arsenate Co2As207,s is known, as also various ammonium arsenates.6... 

If the test is made with the sulphide precipitated in acid solution, only mercury will interfere by converting the arsenic into magnesium ammonium arsenate and heating to redness, the pyroarsenate Mg2As207 remains and any mercury salts present are volatilized. This forms the basis of a delicate test for arsenic. 

Magnesia mixture (see Section III.12, reaction 3) white, crystalline precipitate of magnesium ammonium arsenate Mg(NH4)As04.6HzO from neutral or ammoniacal solution (distinction from arsenite) ... 

If phosphate has been detected previously (e.g. in the cation analysis), a qualitative test for arsenate may be made as follows. Pour 1 ml AgN03 solution, to which 2 drops of dilute acetic acid have been added, over the white precipitate. A brownish-red colouration of the precipitate confirms the presence of arsenate. The acetic acid is added to increase the solubility of the magnesium salt and thus facilitate the conversion of magnesium ammonium arsenate to the characteristic silver arsenate. 

Ammonium arsenates.—Excess of ammonia precipitates normal ammonium arsenate, (NH4)3As04, from concentrated solutions of the primary and secondary salts. It yields a very alkaline solution, decomposed by zinc and by aluminium with evolution of hydrogen and arsine.14 Secondary ammonium arsenate, (NH4)2HAs04, is gradually deposited from a concentrated solution of arsenic acid and ammonium hydroxide.15 Loss of ammonia, or addition of arsenic acid to its solution, converts it into primary ammonium arsenate, NH4H2As04, crystals of density 2-307 16 or 2-3105.17... 

In presence of dilute ammonium hydroxide reduction to metallic silver takes place in three stages, ammonium arsenate and nitrate being simultaneously formed ... 

SYNS AMMONIUM ACID ARSENATE AMMONIUM ARSENATE, soUd pOT) DIAiMMONIUM ARSENATE DIAMMONIUM MONOHYDROGEN ARSENATE DIBASIC AMMONIUM ARSENATE SECONDARY AMMONIUM ARSENATE... 

Zinc Phenolsulfonate Calcium Phenolsulfonate Potassium Borate Titanic Acid Phosphine Sulfur Chloride Sodium Thioarsenate Arsenic Oxide Ammonium Arsenate Chlordane Amyl Acid Phosphate Butylated Hydroxytoluene Soarnol E Mercurochrome Sodium Chloride Sulfate Quinine Hydrochloride Quinine Dichloroethane Calcium Phenolsulfonate Anisoyl Chloride Xylenol... 

De Pasllle reconmiends that ammonium arsenate be reduced in an ammonia stream at 1000°C. According to Geach, very pure As can also be obtained by reduction of chemically pure AS3O3 with Zr metal and subsequent sublimation. Impurities other than Sb can be removed by sublimation in vacuum (Geach). 

Ammonium acetate Ammonium arsenate Ammonium benzoate Ammonium bicarbonate Ammonium bisulfite Ammonium bromide Ammonium carbonate Ammonium chloride Ammonium citrate Ammonium dichromate Ammonium fluoride (1050LF)... 

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