Sulphates forms

Any lead(II) sulphate formed in this process is converted to lead(II) silicate by reaction with the quartz. The oxide produced is then mixed with limestone and coke and heated in a blast furnace. The following reactions occur ... 

Hydrolysis of Potassium Ethyl Sulphate. Dissolve about i g. of the crystals in about 4 ml. of cold distilled water, and divide the solution into two portions, a) To one portion, add barium chloride solution. If pure potassium ethyl sulphate were used, no precipitate should now form, as barium ethyl sulphate is soluble in water. Actually however, almost all samples of potassium ethyl sulphate contain traces of potassium hydrogen sulphate formed by slight hydrolysis of the ethyl compound during the evaporation of its solution, and barium chloride almost invariably gives a faint precipitate of barium sulphate. b) To the second portion, add 2-3 drops of concentrated hydrochloric acid, and boil the mixture gently for about one minute. Cool, add distilled water if necessary until the solution has its former volume, and then add barium chloride as before. A markedly heavier precipitate of barium sulphate separates. The hydrolysis of the potassium ethyl sulphate is hastened considerably by the presence of the free acid Caustic alkalis have a similar, but not quite so rapid an effect. 

Dimethyl sulphate is of particular value for the methylation of phenols and sugars. The phenol is dissolved in a slight excess of sodium hydroxide solution, the theoretical quantity of dimethyl sulphate is added, and the mixture is heated on a water bath and shaken or stirred mechanically (compare Section IV, 104). Under these conditions only one of the methyl groups is utilised the methyl hydrogen sulphate formed in the reaction reacts with the alkali present. -... 

This is in agreement with the suggestion of Vreudge et al. [11], Plack et al [7], and Siyam et al. [19,20]. Copper sulphate forms crosslinked structures with ammonium groups of p(AM-DAA-HCl) and p(AM-DAEA-HCl) are shown in the possible Structure 25 and Structure 26 , respectively. 

Mino and Kaizerman [12] established that certain. ceric salts such as the nitrate and sulphate form very effective redox systems in the presence of organic reducing agents such as alcohols, thiols, glycols, aldehyde, and amines. Duke and coworkers [14,15] suggested the formation of an intermediate complex between the substrate and ceric ion, which subsequently is disproportionate to a free radical species. Evidence of complex formation between Ce(IV) and cellulose has been studied by several investigators [16-19]. Using alcohol the reaction can be written as follows ... 

Reactions of contaminants in the fuel or air in the combustion zone can result in the formation of compounds which can condense as molten salts onto cooler components in the system. This type of process can occur when fuels containing sulphur or vanadium are burnt. In the case of sulphur contaminants, alkali sulphates form by reactions with sodium which may also be present in the fuel or in the combustion air, and for vanadium-containing fuels low-melting-point sodium vanadates or vanadium pentoxide are produced, particularly when burning residual oils high in vanadium. Attack by molten salts has many features in common which will be illustrated for the alkali-sulphate-induced attack, but which will be subsequently shown to be relevant to the case of vanadate attack. 

Self regulating chromium The self-regulating chromium solutions were introduced to eliminate the need for maintaining the correct catalyst concentration by periodic analysis they depend on the addition of a sparingly soluble sulphate to the bath which supplies the correct amount of SO 4 automatically. Initially strontium sulphate (solubility approx. l-75g/l at 30°C and 21 g/1 at 40°C) was employed for this purpose. The strontium sulphate forms a layer on the bottom of the bath, which must be stirred from, time to time. A bath with a CrO, concentration of 250 g/1 would have a catalyst content of l 52g/l SrS04 and 4-35 g/1 of KjSiF. Potassium dichromate and strontium chromate have also found application as additives for the control of the saturation solubility of the catalyst. 

Thiocyanate as BaS04. Treat the alkali thiocyanate solution with excess bromine water and heat for 1 hour on a water bath. Acidify the solution with hydrochloric acid and determine the sulphate formed by precipitating and weighing as BaS04 (Section 11.72) see also Section 11.75. 

When a large excess of ferric ion was employed to promote the sulphate-forming reaction under nitrogen, it was found that a plot of versus [Fe(II)]o + 2 [H2S03]q is a straight line and in general the rate equation... 

Sodium sulphate forms, in the presence of aluminium at 800°C, sodium sulphide. The reaction usually proves to be explosive and the usual method of preparing sodium sulphide from the sulphate uses carbon as a reducing agent. 

Landers et al. [97] and others [98] have described a wet digestion method for the determination of total sulphur in soils. In this method the sample (1.50-500mg) is placed in a digestion flask and heated in a sand bath to dryness at 250°C with 3ml of sodium hypobromite solution. The residue is resuspended with water, neutralized with formic acid, and then hydriodic acid reduction of the sample is followed to quantitatively recover the inorganic sulphate formed by wet oxidation. 

Combustion temperatures are high enough to ensure carbonate decomposition and full oxidation of the sulphur values to the sulphate form. 

Ammino-derivatives of Cupric Sulphate.—Cupric sulphate forms with ammonia four ammino derivatives, namely, pentammino-cupric sulphate, [Cu(NII3)5]S04 tetrammino-cupric sulphate, [Cu(NH3)4]S04 diammino-cupric sulphate, [Cu(NH3)2]S04 and monammino-cuprzc sulphate, [Cu(NH3)]S04. The tetrammino salt is the best known and the one most easily obtained. It exists both in the anhydrous and in the hydrated state. 

The ammine crystallises in hexagonal plates which are colourless, readily oxidised in air, insoluble in alcohol, and decomposed by water. It is stable up to 100° C., but above that temperature loses ammonia, liberating Cu2S04, which then decomposes. The salt reduces nitric acid, and is broken down by dilute sulphuric acid, copper being precipitated and cupric ammonium sulphate formed. 

Many other ammines of silver salts have been prepared thus, silver sulphate forms with ammonia diammino-silver sulphate, [Ag2(NH3)2]S04, and tetrammino-silver sulphate, [Ag(NI-I3)2]2S04. a... 

Ammino-zinc Sulphates.—Zinc sulphate forms, with ammonia, pentammino-zinc sulphate, [Zn(NH3)5]S04 tetrammino-zinc sulphate, [Zn(NH3)4]S04 and diammino-zinc sulphate, [Zn(NH3)2]S04. 

The rhombic bipyramidal crystals of potassium sulphate form an isomorphous group with those of the corresponding salts of rubidium and csesium. The axial ratios and mol. vol. are indicated in Table XXXVI the axial ratios and topical parame.ters of the three last-named salts were determined by A. E. H. Tutton.26... 

E. W. Hilgard verified the conclusion and suggested the reaction as an explanation of the formation of natural soda but G. Lunge showed that dil. soln. are required, and on evaporation, the reaction is reversed. H. Taylor (1851) used barium bicarbonate under similar conditions and R. von Wagner showed that a clear soln. of barium bicarbonate decomposes sodium sulphate, forming barium sulphate and sodium bicarbonate, and that a comparatively small proportion of the bicarbonate will complete the reaction between barium carbonate and sodium sulphate. 

Amidosulphonie acid may also be prepared 5 by passing sulphur dioxide into an aqueous solution of sodium nitrite containing sodium carbonate, until the solution is acid to litmus the nitrilosulphonate which is formed is hydrolysed by the addition of a little concentrated sulphuric acid, amidosulphonate and acid sulphate being formed. The solution is neutralised by the addition of sodium carbonate and the sodium sulphate formed separated by crystallisation the addition of a large excess of concentrated sulphuric acid to the solution then results in the precipitation of amidosulphonie acid. 

When hydrazine sulphate is treated with barium carbonate in hot solution, dihydrazine sulphate forms according to the equation ... 

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