Sulphuric acid chemistry

It is the nitronium ion which is responsible for nitrating actions in organic chemistry which are carried out in a mixture of nitric and sulphuric acids. When nitric acid is dissolved in water, its behaviour is that of a strong acid, i.e. ... 

The corrosion of tin by nitric acid and its inhibition by n-alkylamines has been reportedThe action of perchloric acid on tin has been studied " and sulphuric acid corrosion inhibition by aniline, pyridine and their derivatives as well as sulphones, sulphoxides and sulphides described. Attack of tin by oxalic, citric and tartaric acids was found to be under the anodic control of the Sn salts in solution in oxygen free conditions . In a study of tin contaminated by up to 1200 ppm Sb, it was demonstrated that the modified surface chemistry catalysed the hydrogen evolution reaction in deaerated citric acid solution. 

Bakke et al. (1982) have shown how montmorillonite catalyses chlorination and nitration of toluene nitration leads to 56 % para and 41 % ortho derivative compared to approximately 40 % para and 60 % ortho derivatives in the absence of the catalyst. Montmorillonite clays have an acidity comparable to nitric acid / sulphuric acid mixtures and the use of iron-exchanged material (Clayfen) gives a remarkable improvement in the para, ortho ratio in the nitration of phenols. The nitration of estrones, which is relevant in making various estrogenic drugs, can be improved in a remarkable way by using molecular engineered layer structures (MELS), while a reduction in the cost by a factor of six has been indicated. With a Clayfen type catalyst, it seems possible to manipulate the para, ortho ratio drastically for a variety of substrates and this should be useful in the manufacture of fine chemicals. In principle, such catalysts may approach biomimetic chemistry our ability to predict selectivity is very limited. 

Carlson et al. (1999b) compared laboratory spectra and Galileo data and suggested that hydrated sulphuric acid is the main component in the dark surface material, which probably also contains sulphur polymers modified by radiation chemistry. A sulphur cycle involving three sulphur species is suggested sulphuric acid (H2SO4), sulphur dioxide (SO2) and sulphur polymers (S ). 

Dinkevich F.E., Juravel T.A., Ksenzhek O.S. and Lobach G.A. The Solubility of Some Quinon Compounds in the Sulphuric Acid Solvents. (Rus.), Problems of Chemistry and Chemical Technology IVoprosy Khimii i Khimicheskoy Tekhnologiil (Ukrainian Journal). 1979 55 10-12. 

Zhu, X. P., Kotowski, M., Pawlowski, L., The relative importance of aluminum solid-phase component in agricultural soils treated with oxalic and sulphuric acids, in Chemistry for the Protection of the Environment, 3, eds. L.Pawlowski, M.A. Gonzalez,... 

Analogy with sulphur chemistry is useful here. If one OH group in sulphuric acid is replaced by a H atom, the hypothetical sulphooio acid (IV) is obtained. 

The isolation of tryptophane by Hopkins and Cole in 1902 from the mixture of products formed by the tryptic digestion of caseinogen by precipitation in sulphuric acid solution with mercuric sulphate, besides adding to our list of foundation-stones or units of the protein molecule, gave us the explanation of three phenomena long known in connection with the chemistry of the proteins, namely (i) of the reddish-... 

In 1976 he was appointed to Associate Professor for Technical Chemistry at the University Hannover. His research group experimentally investigated the interrelation of adsorption, transfer processes and chemical reaction in bubble columns by means of various model reactions a) the formation of tertiary-butanol from isobutene in the presence of sulphuric acid as a catalyst b) the absorption and interphase mass transfer of CO2 in the presence and absence of the enzyme carboanhydrase c) chlorination of toluene d) Fischer-Tropsch synthesis. Based on these data, the processes were mathematically modelled Fluid dynamic properties in Fischer-Tropsch Slurry Reactors were evaluated and mass transfer limitation of the process was proved. In addition, the solubiHties of oxygen and CO2 in various aqueous solutions and those of chlorine in benzene and toluene were determined. Within the framework of development of a process for reconditioning of nuclear fuel wastes the kinetics of the denitration of efQuents with formic acid was investigated. 

Hanson, D.R., and Ravishankara, A.R. (1995) Heterogeneous chemistry of bromine species in sulphuric acid under stratospheric conditions, Geophys. Res. Lett. 22,385-388. 

Georg Bredig (1868-1944)137 138 was essentially a physical chemist, who worked in catalysis, reaction kinetics, and electrochemistry. For physical organic chemistry his studies of the catalysed decomposition of diazoacetic ester, of reactions in concentrated sulphuric acid, and of the catalysis of the benzoin condensation by cyanide ion are of interest. The last-mentioned work was done in 1904, when Bredig confirmed,... 

The product is a sulphuric acid ester or sulpho acid which is susceptible to acid hydrolysis, reverting to the alcohol and free sulphuric acid. Since the rate of hydrolysis is dependent on the concentration of the acid, the hydrolysis reaction is effectively self-catalysing so that the sulpho acid must be neutralised as quickly as possible after manufacture to prevent reversion. This simple chemistry has a profound effect on the manufacture, use and economics of alkyl sulphates. 

---