Sulphate composition

Sivakumar, S. R. and Arunkumar, K. (2009). Sodium, potassium and sulphate composition in some seaweeds occurring along the coast of Gulf of Mannar, India. Asian ]. Plant Sci. 8,... 

These are a relatively new development. They are low-melting-point glasses which can be blended with certain organic polymers and injection moulded to give products with superior thermal and dimensional stability. They include alkali/zincpyrophosphate/sulphate compositions (Table 12.26) [62]. 

The method used to contact the alloys and the sulphates did not greatly influence the final distribution of metals between oxidation products. The most irrpcrtant characteristics determining the processing parameters were the sulphate composition and the initial conposition of the alloys. The average total oxidation rates of conponents were close to previous values [3] and were satisfactorily described by a equation characterising the processes with a predominant role for mass transfer in the liquid phase ... 

Gardette, M., Therias, S., Gardette, J.-L., Murariu, M., Dubois, P. Photooxidation of polylactide/calcium sulphate composites. Polym. Degrad. Stab. 96, 616-623 (2011)... 

Why is potassium aluminium sulphate not soluble in benzene A compound M has the composition C = 50.0% H=12.5%o A1 = 37.5%. 0.360 g of M reacts with an excess of water to evolve 0.336 1 of gas N and leave a white gelatinous precipitate R. R dissolves in aqueous sodium hydroxide and in hydrochloric acid. 20 cm of N require 40 cm of oxygen for complete combustion, carbon dioxide and water being the only products. Identify compounds N and R, suggest a structural formula for M, and write an equation for the reaction of M with water. (All gas volumes were measured at s.t.p.)... 

To appreciate the action of a drying agent of class (a), let us imagine some anhydrous copper sulphate in an evacuated vessel provided with a pressure gauge, and water is allowed to enter slowly the temperature is assumed constant at 25°. The results may be best expressed by means of a vapour pressure - composition diagram (Fig. 7, 20, 1). The initial system is represented by the point A the pressure will rise along AB until the monohydrate CuS04,H20 commences to form at B. 

Gum turpentine is obtained from wounding living trees to get an exudate containing turpentine and rosin. Turpentine is separated from the rosin by continuous steam distillation and further fractionation. Wood turpentine comes from the extraction of stumps of pine trees using naphtha, and subsequent separation of rosin and turpentine by fractional distillation. Tail-oil turpentine is a byproduct of the Kraft sulphate paper manufacture. Terpenes are isolated from the sulphate terpentine and separated from the black digestion liquor. The composition of turpentine oils depends on its source, although a-pinene and p-pinene are the major components. 

Erythrophleine, C24H3,OgN. This formula, adopted by Blount, Openshaw and Todd, is based on analyses of the sulphate B. 0 5HgSO4, and on the composition of the well-defined hydrolytic products, prepared... 

Cinders and acid peaty soils are obviously among the soils most corrosive toward copper. There is, however, no direct relationship between the rate of corrosion and any single feature of the soil composition or constitution". For instance, in the American tests corrosion in several soils with either low pH or high conductivity was not particularly severe, while the British tests show that high chloride or sulphate contents are not necessarily harmful. 

Vernon claims that in outdoor atmospheres the corrosion product consists largely of zinc oxide, hydroxide and combined water, but also contains zinc sulphide, zinc sulphate and carbonate. The following table gives the composition of typical films formed in an industrial atmosphere. 

The ash deposits resulting from the combustion of solid and oil fuels often contain appreciable quantities of other corrodants in addition to vanadium pentoxide. One of the more important of these is sodium sulphate, and the effects of this constituent in producing sulphur attack have been mentioned. The contents of sodium sulphate and vanadium pentoxide present in fuel oil ash can vary markedly and the relative merits of different materials depend to a great extent upon the proportions of these constituents. Exposure of heat-resisting alloys of varying nickel, chromium and iron contents to ash deposition in the super-heater zones of oil-fired boilers indicated a behaviour pattern depending on the composition of the alloy and of the ash... 

The furnace scales which form on alloy steels are thin, adherent, complex in composition, and more difficult to remove than scale from non-alloy steels. Several mixed acid pickles have been recommended for stainless steel, the type of pickle depending on the composition and thickness of the scale For lightly-scaled stainless steel, a nitric/hydrofluoric acid mixture is suitable, the ratio of the acids being varied to suit the type of scale. An increase in the ratio of hydrofluoric acid to nitric acid increases the whitening effect, but also increases the metal loss. Strict chemical control of this mixture is necessary, since it tends to pit the steel when the acid is nearing exhaustion. For heavy scale, two separate pickles are often used. The first conditions the scale and the second removes it. For example, a sulphuric/hydrochloric mixture is recommended as a scale conditioner on heavily scaled chromium steels, and a nitric/hydrochloric mixture for scale removal. A ferric sulphate/ hydrofluoric acid mixture has advantages over a nitric/hydrofluoric acid mixture in that the loss of metal is reduced and the pickling time is shorter, but strict chemical control of the bath is necessary. 

The sulphate bath The sulphate bath, the earliest of electroplating solutions and the simplest in composition, contains typically 150-250 g/1 of copper sulphate and 40-120 g/1 of sulphuric acid. The composition is not critical and the higher concentrations are used for plating at higher current densities, normally up to 6 A/dm. ... 

Most nickel electroplating is carried out in solutions based oh the mixture of nickel sulphate, nickel chloride and boric acid proposed, by O. P., Watts . Typical composition and operating conditions are ... 

Composition of the liquid environment The ionic composition, arising from dissolved salts and gases, has a considerable influence on the performance of inhibitors. In near-neutral aqueous systems the presence of certain ions tends to oppose the action of inhibitors. Chlorides and sulphates are the most common examples of these aggressive ions, but other ions, e.g. halides, sulphides, nitrates, etc. exert similar effects. The concentration of inhibitor required for protection will depend on the concentrations of these aggressive ions. Laboratory tests " have given some quantitative relationships... 

Procedure. The sample solution should preferably contain titanium as sulphate in sulphuric acid solution, and be free from the interfering constituents mentioned above. The final acidity may vary from 0.75 to 1.75M. If iron is present in appreciable amounts, add dilute phosphoric(V) acid from a burette until the yellow colour of the iron(III) is eliminated the same amount of phosphoric(V) acid must be added to the standards. If alkali sulphates are present in the test solution in appreciable quantity, add a like amount to the standards. Add 10 mL of 3 per cent hydrogen peroxide solution and dilute the solution to 100 mL in a graduated flask the final concentration of Ti may conveniently be 2-25 parts per million. Compare the colour produced by the unknown solution with that of standards of similar composition by any of the usual methods. 

A. Molybdenum blue method Discussion. Orthophosphate and molybdate ions condense in acidic solution to give molybdophosphoric acid (phosphomolybdic acid), which upon selective reduction (say, with hydrazinium sulphate) produces a blue colour, due to molybdenum blue of uncertain composition. The intensity of the blue colour is proportional to the amount of phosphate initially incorporated in the heteropoly acid. If the acidity at the time of reduction is 0.5M in sulphuric acid and hydrazinium sulphate is the reductant, the resulting blue complex exhibits maximum absorption at 820-830 nm. 

All commercial materials are based on calcium hydroxide and liquid alkyl salicylates (Prosser, Grolfman Wilson, 1982) and are supplied as a two-paste pack. Zinc oxide is sometimes added to the calcium hydroxide, as are neutral fillers. A paste is formed from this powder by the addition of a plasticizer examples include A-ethyl toluenesulphonamide (o- orp-) and paraffin oil, with sometimes minor additions of polypropylene glycol. The other paste is based on an alkyl salicylate as the active constituent containing an inorganic filler such as titanium dioxide, calcium sulphate, calcium tungstate or barium sulphate. Alkyl salicylates used include methyl salicylate, isobutyl salicylate, and 1-methyl trimethylene disalicylate. An example of one commercial material, Dycal, is given in Table 9.7, but its composition has been subjected to change over the years. 

Taylor, B.E., M. C. Wheeler and D.K. Nordstrom, 1984, Isotope composition of sulphate in acid mine drainage as measure of bacterial oxidation. Nature 308, 538-541. 

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