Ammonium bisulphate

The esterified stream, which may contain inhibitors to prevent premature polymerisation, is then passed to a stripping column which separates the methyl methacrylate, methanol and some water from the residue made up of sulphuric acid, ammonium bisulphate and the remainder of the water. The methyl methacrylate is subsequently separated and purified by further distillation. 

The use of sulphamic acid (12.1) has been recommended, resulting in a shift of pH from 1.8 to between 3.0 and 3.5 as the temperature approaches the boil, thus giving rise to less fibre damage. Typically, 6% o.w.f. sulphamic acid is added, together with an auxiliary and sodium sulphate. The change in pH arises as a result of hydrolysis of the sulphamic acid to give ammonium bisulphate (Scheme 12.1) [2,5]. 

The ACH process has recently been improved, as stated by Mitsubishi Gas. Acetone-cyanohydrin is first hydrolized to 2-hydroxyisobutylamide with an Mn02 catalyst the amide is then reacted with methylformiate to produce the methyl ester of 2-hydroxyisobutyric acid, with coproduction of formamide (this reaction is catalyzed by Na methoxide). The ester is finally dehydrated with an Na-Y zeolite to methylmethacrylate. Formamide is converted to cyanhydric acid, which is used to produce acetone-cyanohydrin by reaction with acetone. The process is very elegant, since it avoids the coproduction of ammonium bisulphate, and there is no net income of HCN. Problems may derive from the many synthetic steps involved, and from the high energy consumption. 

Ammonium bisulphate [7803-63-6] M 115.1°. Crystd from water at room temperature (Iml/g) by adding EtOH and cooling. 

The Treatment of Special Ores.—Alumina does not appear to induce retrogression. It may be removed by caustic alkalies or hot alkali carbonate solutions. Redonda phosphate (A1P04) may be made soluble by fusion with ammonium bisulphate, giving a dry powder which is a mixture of ammonium alum, ammonium bisulphate and biphosphate. 

Table 17. The influence of breathing pattern on ammonium bisulphate deposition in the lung Reproduced from Pritchard JN (1987). Particle growth in the airways and the influence of airflow.

The ore mineral can also be treated by fusing it with ammonium bisulphate or caustic soda, or by digestion with hydrofluoric acid or sulphuric acid, or mixtures of the two (Gupta and Krishnamurthy 2005). 

Similar geometry for HSOi" is found in ammonium bisulphate. S-OH distances in the two independent anions are 1.546 and 1.557 A whereas S-O distances lie between 1.419 and 1.455 A HO-S-O angles are generally greater than 109° and O-S-0 angles smaller. 

The Kjeldahl method converts the bonded nitrogen into ammonium bisulphate which is then determined as ammonia. Many variations have been introduced in order to refine the method or... 

The hydrogensulphates (or bisulphates) containing the ion HSO4, are only known in the solid state for the alkali metals and ammonium. Sodium hydrogensulphate is formed when sodium chloride is treated with cold concentrated sulphuric acid ... 

Sodium aluminium sulphate Sodium bisulphate Sodium hypochlorite Sodium perchlorate Sodium thiocyanate Stannic ammonium chloride Stannic chloride Stannous chloride Uranyl nitrate Zinc chloride Zinc fluorosilicate... 

The electrical conductivities of soln. of a great many compounds in liquid hydrogen halides have been measured by E. H. Archibald and D. McIntosh. The conductivity is raised considerably by phosphoryl chloride. Sodium sodium sulphide, borate, phosphate, nitrate, thiosulphate, and arsenate chromic anhydride potassium nitrate, hydroxide, chromate, sulphide, bisulphate, and ferro- and ferri- cyanide ammonium fluoride and carbonate j rubidium and caesium chloride magnesium sulphate calcium fluoride ... 

Heavy Metals. — The solution of 1 gm. of potassium bisulphate in 20 cc. of water should not be affected by hydrogen sulphide water nor by ammonium sulphide solution when rendered slightly alkaline with ammonia water. 

Uranium minerals may be obtained in solution, in a suitable condition for estimation, by the following process. The ore is dissolved in aqua regia, or, if necessary, fused with alkali bisulphate and extracted mth hot hydrochloric acid. After evaporation to drjmess, the residue is taken up with dilute hydrochloric acid, and the solution saturated with hydrogeir sulphide in order to remove any copper, lead, bismuth, arsenic, antimony, or any other metal yielding an insoluble sulphide. The filtrate is concentrated and treated with ammonium carbonate, which precipitates the carbonates of the alkaline earths, iron, and most of the rare earths. The filtrate is neutralised by hydrochloric acid, evaporated to dryness, and the residue ignited to drive off ammonium salts, and then redissolved in dilute acid. The remaining rare earths, and particularly thorium, are next precipitated by the addition of oxalic acid. The filtrate, which contains the uranium in the uranyl condition, may now be precipitated by any of the methods described above. 

Vinylidene fluoride and hexafluoropropylene Ammonium persulphate Sodium bisulphate... 

Solvents such as 97% sulphuric acid and molten ammonium hydrogen sulphate are much further removed from water than any solvent mentioned so far in this section. Kinetic studies of the decomposition of [Co(NH3)e] + and of [Co(NH3)5(S04)]+ in these solvents have indicated that the rate-determining step is a substitution process, in which ammonia is replaced by bisulphate. The activation energy for such a process is about 40kcalmol" in these solvents. This slow substitution is followed by more rapid redox processes. 

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