Hydrogensulphates

The extent of dissociation at a given temperature can be determined by measuring the density of the vapour. Since anhydrous sulphuric acid is less volatile than hydrogen chloride, ammonium sulphate does not readily sublime on heating some ammonia is evolved to leave the hydrogensulphate ... 

On a large scale, hydrogen peroxide is produced by the electrolysis of ammonium hydrogensulphate, using a platinum anode and a lead cathode separated by a diaphragm. The essential process occurring is ... 

The ammonium hydrogensulphate is returned to the electrolytic cell. A process such as this yields an aqueous solution containing about 30% hydrogen peroxide. The solution can be further concentrated, yielding ultimately pure hydrogen peroxide, by fractional distillation but the heating of concentrated hydrogen peroxide solutions requires care (see below). 

The nitrosyl hydrogensulphate formed can also react in two ways, viz. ... 

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 ... 

The hydrogensulphate ion dissociates into hydrogen and sulphate ions in solution hence hydrogensulphates behave as acids. 

When solid sodium hydrogensulphate is heated, sodium pyro-sulphate is formed further heating gives sodium sulphate and sulphur trioxide ... 

Electrolysis of the hydrogensulphate of potassium or ammonium can yield a peroxodisulphate and thence hydrogen peroxide. 

Fusions with (a) sodium carbonate or fusion mixture, (b) borax and lithium metaborate, (c) alkali bifluorides, and (d) alkali hydrogensulphates (slight attack in the last case above 700 °C, which is diminished by the addition of ammonium sulphate). 

A mixture of ethanol and acetic anhydride detonated and the compounds combusted causing a fire when sodium hydrogensulphate was introduced into the mixture by mistake. The acid nature of this salt obviously catalysed this alcoholysis. 

DIpotasslum hydrogenphosphate Potassium hydroxide Potassum hydrogensulphate Lithium hydroxide Hydrogens ... 

Fig. 3.107. Comparison of micro-HPLC separations of aromatic sulphonic acids in different mobile phases (a) 0.005 M tetrabutylammonium hydrogensulphate (TBAS) in 15 per cent (v/v) methanol in water (1) Laurent acid, (2) amino-F-acid, (3) Cleve-1,6- and Peri acids, (4) unidentified impurity, (5) Cleve-1,7-acid and (6) unidentified impurity, (b) 0.005 M tetrabutylammonium hydrogensulphate (TBAS) in 15 per cent (v/v) methanol in water with 0.01 M /Lcyclodextrin (CD) (1) Laurent acid, (2) amino-F-acid, (3) Cleve-1,6-acid, (4) Peri acids, (5) unidentified impurity, (6) Cleve-1,7-acid and (7) unidentified impurity. Column, Biosphere Si C18, 162 X 0.32 mm i.d. flow rate 5 pl/min, column temperature ambient, detection, UV, 220-230 nm. Reprinted with permission from P. Jandera et al. [164].

TBA-HS04 (0.6 g, 1.77 mmol) is added to the inflate sugar (0.85 mmol) in MeCN (15 ml) at 0°C and the mixture is stirred at room temperature until TLC analysis indicates complete consumption of the triflate ester (ca. 12 h). The solvent is evaporated and the residue recrystallized to yield the hydrogensulphate ester or the cyclic ester. 

The tautomerism of 1-nitroprop-l-enyl sugars into a,p-unsaturated oximes is catalysed by potassium fluoride in the presence of tetra-n-butylammonium hydrogensulphate, providing a route to 1,3-dicarbonyl sugar derivatives [7],... 

Hydride ion transfer from formic acid and its salts finds widespread application in the reduction of organic substrates, but limited use has been made of the procedure under phase-transfer catalytic conditions. However in the presence of a ruthenium complex catalyst, it is possible to selectively reduce the C=C bonds of conjugated ketones with sodium formate [11], The rate of reduction is fastest with tetrahexyl-ammonium hydrogensulphate and Aliquat the complete reduction of chalcone being effected within one hour, whereas with benzyltriethylammonium chloride only ca. 15% reduction is observed after two hours under similar conditions. 

Sulphonation Aniline reacts with concentrated sulphuric acid to form anlllnlum hydrogensulphate which on heating with sulphuric acid at 453-473K produces p-amlnobenzene sulphonlc acid, commonly known as sulphanlkc acid, as the major product. 

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