Disulphuric acid

Peroxymono- and disulphuric acids detonate in contact with phenol,... 

Cone. soln. of two mol. eq. of sodium nitrite and one of sodium carbonate are treated with sulphur dioxide until the mixture has an acid reaction. The sodium salt of hydroxylamine disulphuric acid, H0.N(HS03)s> is formed, and this decomposes on the addition of a little sulphuric acid into the sodium salt of hydroxylamidosulphonie acid, HO-NH.HSO, and sodium hydrosulphate, NaHS04. When the first-named salt has stood a couple of days at 90°-95°, it breaks down still further into hydroxylamine, HO-NHj, and sodium bisulphate. The latter is first crystallized from the soln., and crystals of hydroxylamine sulphate are subsequently separated. Potassium salts do not give so good a yield as the sodium salts. Very little ammonia is formed. W. L. Semon modified this process. 

SYNS DISULPHURIC ACID DITHIONIC ACID FUMING SULFURIC ACID OLEUM PYROSULPHURIC ACID SULFURIC ACID, fiming > or =30% free sulfur trioxide (DOT) SULFURIC ACID, fuming <30% free sulfur trioxide (DOT) SULFURIC ACID MIXTURE with SULFUR TRIOXIDE... 

Haywood and Riley showed that tetraphenylarsonium chloride, l- o-arsonophenyl-azo)-2-naphthol-3,6-disulphuric acid and o-arsonophenylazo-p-dimethylaminobenzene are quantitatively decomposed in seawater by ultraviolet radiation, and 98% of the As can be recovered. 

Until recently its manufacture was based on the electrolysis of ammonium sulphate in an excess of sulphuric acid between platinum electrodes at high current density this produces a solution of the ammonium salt of per-disulphuric acid by oxidation at the anode and liberates hydrogen at the cathode ... 

According to Nielsen [16] the method consists in the action of peroxy-disulphuric acid S2 Og ... 

The nature of mixed cations of sulphur in H2S2O7 has been studied. Elemental sulphur, SCI, and SCI2 were added to disulphuric acid, sometimes in the presence of halogens. Cryoscopic and conductance measurements enabled equations to be proposed to account for all the observed reactions. The blue coloration due to the ion was observed when SCI and SCI2 were dissolved in H2S2O7 ... 

Heparin, de-esterified nitrated hyaluronic acid, the related sulphonic acid dyes (e.g. chlorazol fast pink) and a non-specific inhibitor of rabbit and human serum, all inhibit various hyaluronidases from different sources but there are great differences, depending on substrate, enzyme and inhibitor. As inhibitors, cellulose trisulphuric acid and chitin disulphuric acid are much stronger, while treburon is similar to heparin. 

The spectral maxima at 320, 390, and 590 nm were found to correspond to absorptions by the ions S , S , and S7, respectively. Direct observations (resonance Raman, i.r., and e.s.r. spectra) and indirect measurements (visible— u.v. spectra, conductivity, and magnetic susceptibility) strongly suggest that the intensely blue species formed by alkali-metal polysulphides or elemental sulphur in hexamethylphosphoramide can be attributed to the Sj radical anion. Cryoscopic, conductance, and magnetic measurements euid i.r. and u.v. spectral data have been used to study the cations formed in solutions of sulphur in disulphuric acid. The blue coloration was shown to be due to the formation of the Si" " ion and the colourless solutions were found to contain the S ion. The solid compounds S4S30ioand 8383010, formed by the action of SO3 on elemental sulphur in 8O2 media at low temperatures, have been isolated and characterized. 

There are only a few known substances which act as acids in sulphuric acid. Even perchloric acid, the strongest mineral acid in water, is undissociated in sulphuric acid despite the high dielectric constant. Disulphuric acid and higher polysulphuric acids are definitely acidic as well as the complex acid HB(HS04)4, which is obtained by dissolving boric acid in oleum o. 

After the ionizing properties of fluorosulphuric acid were discovered and more extensively studied 3-95 similar phenomena were observed in chloro-sulphuijic acid , difluorophosphoric acid " and disulphuric acid . Their solvent properties resemble those of sulphuric acid. 

Sulphuric acid is a strongly acidic solvent in which a very large number of substances exhibit basic behaviour, i.e. are protonated by the solvent, but very few exhibit acidic behaviour, i.e. are capable of protonating the solvent. An example of an acid of the sulphuric acid solvent system is disulphuric acid H2S2O7, which is partially ionized in solution in sulphuric acid according to the equation ... 

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