Ammonium Salts Sulphate

Although more widely applicable to organic chemicals, the matrix of some inorganic chemicals may be reduced or modified by heating to an elevated temperature. Care must be exercised not to lose volatile trace metals such as arsenic, cadmium and zinc mercury will almost invariably be lost to some extent. Matrices which might be amenable to this treatment include ammonium salts, sulphates, nitrates and the salts of organic acids such as the oxalates. 

Procedure. A. Nickel in a nickel salt. Weigh out accurately 0.3-0.4g of pure ammonium nickel sulphate (NH4)2S04-NiS04,6H20 into a 500mL beaker provided with a clockglass cover and stirring rod. Dissolve it in water, add 5 mL of dilute hydrochloric acid (1 1) and dilute to 200 mL. Heat to 70-80 °C,... 

A review of earlier results is included in a paper by Kiyoura and Urano [946] on the decompositions of (NH4)2S04 (413—513 K) and NH4HS04 (433-473 K). The intermediate formation at 433 K of the double salt (NH4)3H(S04)2 was detected by X-ray diffraction and this salt decomposed to NH4HS04 at 453 K. Decomposition of the ammonium hydrogen sulphate at 473 K proceeded through the formation of molten sulphamic acid... 

When hot, ammonia and compounds, which contain nitrogen-hydrogen bonds eg ammonium salts and cyanides react violently with chlorates and alkaline perchlorates. Diammonlum sulphate, ammonium chloride, hydroxyl-amine, hydrazine, sodamide, sodium cyanide and ammonium thiocyanate have been cited. So far as hydrazine is concerned, the danger comes from the formation of a complex with sodium or lithium perchlorate, which is explosive when ground. Many of these interactions are explosive but the factors which determine the seriousness of the accident are not known. 

The use of barium sulphide as a secondary sulphidizer [4] was examined on oxidized lead ores from Sicily (BaS). The results obtained were encouraging. Sulphidization using Na2S can also be improved with the use of ammonium salts (chloride and sulphate). These reagents are used in cases where the ore contains clay minerals and calcium carbonate, which prevents suphidization due to the production of soluble calcium bicarbonate. The ammonium increases the solubility of calcium carbonate and improves sulphidization. 

Ammonium ceric sulphate serves as a powerful oxidizing agent in an acidic medium. The salt has a bright yellow colour and so its solution. On reduction, the resulting cerous salt obtained is colourless in appearance and, therefore, strong solutions may be considered as self-indicating. In general practice, 0.05 N solutions are employed invariably for estimations. As this concentration is very dilute for observation of the respective end-point, hence the inclusion of an appropriate indicator becomes necessary. The oxidation reaction involved may be expressed as follows ... 

Because of their high lipophobic character, compared with other ammonium salts, quaternary ammonium hydroxides are not readily prepared by liquidrliquid anion exchange. Only with quaternary ammonium hydrogen sulphates is it possible to transfer the ammonium hydroxide into the organic phase in any viable degree of concentration [30] and this procedure remains the cheapest and simplest procedure. Other methods include treatment of quaternary ammonium halides with silver oxide [31] and by anion exchange using polymer bound hydroxide [e.g. 32]. 

The use of cerium(IV) salts as catalytic oxidation mediator is restricted by their insolubility in non-aqueous media. Cerium(IV) ammonium nitrate (CAN) may be used in organic solvents upon the addition of quaternary ammonium salts, but cerium(IV) sulphate is not transferred under analogous conditions. Bis(tetra-/t-butyl-ammonium) hexanitratocerate(IV) is obtained in a solid form by metathesis of CAN... 

The metal-catalysed autoxidation of alkenes to produce ketones (Wacker reaction) is promoted by the presence of quaternary ammonium salts [14]. For example, using copper(II) chloride and palladium(II) chloride in benzene in the presence of cetyltrimethylammonium bromide, 1-decene is converted into 2-decanone (73%), 1,7-octadiene into 2,7-octadione (77%) and vinylcyclohexane into cyclo-hexylethanone (22%). Benzyltriethylammonium chloride and tetra-n-butylammo-nium hydrogen sulphate are ineffective catalysts. It has been suggested that the process is not micellar, although the catalysts have the characteristics of those which produce micelles. The Wacker reaction is also catalysed by rhodium and ruthenium salts in the presence of a quaternary ammonium salt. Generally, however, the yields are lower than those obtained using the palladium catalyst and, frequently, several oxidation products are obtained from each reaction [15]. 

Mineral fillers and additives aluminium trihydrate (ATH), magnesium hydroxide and boron derivates are the best known but tin derivates, ammonium salts, molybdenum derivates and magnesium sulphate heptahydrate are used to varying extents and nanofillers are developing. 

The cuprous salt. [Cr(NH3)2(SCN)4]Cu, is precipitated from the ammonium salt by the addition of cupric sulphate and sulphur dioxide as a yellow powder. 

The dithionate, like the sulphate of the corresponding ammino-salts, is very sparingly soluble in water, and the other salts may be obtained from it by decomposing it with ammonium salts of the acid. They decompose on treatment with concentrated hydrochloric acid thus ... 

Tetrammino-palladous Hydroxide, [Pd(NII3)4](OH)2, may be obtained by decomposing the sulphate with barium hydroxide. It separates as a colourless crystalline substance which is soluble in water and has a strong alkaline reaction. The aqueous solution is capable of precipitating copper, iron, cobalt, and nickel from solutions of their salts, and it also decomposes ammonium salts. 

Normal ammonium sulphate is used in preparing ammonia and the ammonium salts it is used as a fertilizer it has been used in purifying sulphuric acid from nitrogen oxy-compounds in the fermentation industries and in making freezing mixtures. 

According to the ionic hypothesis, if the solubility product [Li]2[C0"3] is not altered, the solubility can be increased by the union of one or other of the ions of the carbonate forming complexes with the added salt. This effect is not very marked with potassium or sodium chloride or nitrate. The marked increase in the solubility with sodium and potassium sulphates is due to the formation of lithium sulphate, but with the ammonium salts soluble complexes like Li(NH3) and NH2C00 may be formed just as is the case with magnesium carbonate in the presence of ammonium salts. 

This salt was discovered by J. R. Glauber 1 in 1659 he prepared it by the action of nitric acid on volatile alkali—ammonium carbonate—and called it nitrum jlammans. Ammonium nitrate is an artificial product, its occurrence in nature is quite exceptional. Ammonium nitrate, sulphate, and carbonate occur in small quantities in the atm. from which they are carried by rain and snow to the surface waters of the earth. A. Bobierre 2 measured the amount, month by month, in the air of Nantes R. A. Smith determined the amount in the air of towns, etc., in Great Britain C. Ochsenius, in the air of Paris and A. Levy, and F. Fischer,... 

P. A. H. Schreinemakers and P, H. J. Hoenen 20 found that aq. soln. of ammonium sulphate and nitrate furnish two complex salts, ammonium nitrato-sulphate, (NH gSOi-NI NOs, and ammonium (Unitrato-sulphate, (NH4)2S04.2NH4N03. Both salts are decomposed by water, but are stable in the presence of an excess of ammonium nitrate. 

Preparation of a Complex Ammonium Salt of Copper(II). Dissolve 0.5 g of finely triturated copper(II) sulphate pentahydrate in 12.5 ml of a 15% ammonia solution. If the solution is turbid, filter it. Slowly add 7.5 ml of ethanol to the filtrate and let it stand for a few hours in the cold. Filter off the formed crystals, wash them first with a mixture of ethanol and a concentrated ammonia solution (1 1), and then with ethanol and ether. Dry them at room temperature. Into what ions does the product dissociate in the solution Consider the structure of the complex ion from the viewpoint of the valence bond theory. 

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