Sulfuric and Phosphoric Acids

SCHEME 6.4 Construction of (a) H3PO4 and (b) H2SO4. Electrons participating in connectivity are marked in red. The specified numbers of electrons around P and S indicate the 

Terrestrial sulfuric acid is generated naturally due to oxidation of materials containing sulfur, and due to acid rain, which is formed when SO2 is oxidized in the atmosphere to SO3, which together with water forms the acid. There is also extraterrestrial sulfuric acid, due to the oxidation of sulfur, for example, on Venus. Some marine algae use concentrated H2SO4 as a means of protection. 

By the way, H2SO4 is a molecule that starred in a movie. This is Luc Besson s movie. La Femme Nikita, which is about a convicted woman who, instead of serving 

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Lead shows excellent resistance to phosphoric and sulfuric acid in almost all concentrations and at elevated temperatures, as well as to sulfide, sulfite, and sulfate solutions. The corrosion film is insoluble lead sulfate which rapidly reforms if it is damaged. Lead is also resistant to chlorides, fluorides, and bromates at low concentrations and low temperatures. However, because lead is soluble in nitric and acetic acids, it is not resistant to these acids. 

Silver [7440-22-4]—The coloi additive silvei (EEC No. E 174) is a crystaUine powdei of high purity silver prepared by die reaction of silver nitrate with ferrous sulfate in the presence of nitric, phosphoric, and sulfuric acids. Poly(vinyl alcohol) is used to prevent the agglomeration of crystals and the formation of amorphous silver. 

This process produces polymer gasoline with a high octane. Dimerization was first used (1935) to dimerize isobutylene to diisobutylene, constituted of 2,4,4-trimethyl-1-pentene (80%) and 2,4,4-trimethyl-2-pentene (20%). Both phosphoric and sulfuric acid were used as catalysts. 

Polyolefins are resistant to aqueous solutions of inorganic acids such as hydrochloric, phosphoric, and sulfuric acids. These polymers are also resistant to chromic and nitric acids but react with them as well as with dinitrogen tetroxide at elevated temperatures. Polymers with tertiary hydrogen atoms, such as PP, are more readily oxidized than those with only secondary hydrogen atoms, such as hope. 

Collection properties were excellent for the vapor-forming acids, but a greater collection capability was required for the aerosol-forming acids, phosphoric and sulfuric acids. 

Sampling and Analytical Precision and Accuracy. The accuracy of results obtained from a sampling and analytical method are determined by comparison with an independent method. The aerosols of phosphoric and sulfuric acids were collected on mixed cellulose ester filters (14 ) and analyzed by ion chromatography. Table V shows the collection efficiency of the 7-mm O.D./700-mg silica gel collection tubes with respect to the results obtained from filter samples, and the precision obtained from calculation of the pooled relative standard deviation. 

Although a large number of acids are known to the chemist, only a few of them are produced by the chemical industries on a tonnage basis. Of these, the most important are hydrochloric, nitric, phosphoric, and sulfuric acids. 

In like manner, inclusion of mineral acid in the photo-sensitised grafting of styrene in methanol to cellulose enhances the polymerisation yields significantly (Figure 2). The results obtained with phosphoric and sulfuric acids were consistent with earlier data (13,14). Dioxan is also a useful solvent for these reactions when uranyl ion is used as sensitiser. However dioxan is not as efficient as methanol for the grafting reaction. The grafting in dioxan exhibits a Trommsdorff peak at 60% monomer concentration. The results in Figure 2 also show that the unsensitised process does occur in dioxan as in other solvents, but... 

CNC LEVELER JH is compatible with high amounts of phosphoric and sulfuric acids also with large amounts of sodium hydroxide and potassium hydroxide. 

Deprotenized mbber (DPNR) — this is very useful when low water absorption is wanted, vulcanizates with low creep are needed, or more than ordinary reproducibility is required. Normally NR has between 0.25 and 0.5% nitrogen as protein DPNR has only about 0.07%. A drawback is that since protein matter in the mbber accelerates cure, DPNR requires more acceleraticm. DPNR is made by treating NR latex with bioenzyme, which hydrolyzes the proteins to water-soluble forms. A protease like Bacillus subtilis is used at about 0.3 phr. When the enzymolysis is completed the latex is diluted to 3% total soUds and coagulated by adding a mixture of phosphoric and sulfuric acid. The coagulated mbber is then pressed free of most of the water, cmmbed, dried, and baled. 

Acetoacetic ester, MeC0CH2C02Et, was found to be a new substrate for the B-R reaction in both phosphoric, and sulfuric acid media by Dutt and Banerjee (1981-1). They determined the limits of the concentration range of each component. The mechanism was related to the model given by Noyes, et al. for the Belousov-Zhabo-tinskii reaction. Dutt and Banerjee (1981-2) were also able to observe oscillations in hydrochloric acid medium and in phosphoric acid that included chloride ions, CT7H3PO4. The induction period for oscillations increases with increased chloride ion concentration and oscillations are not observed when the chloride concentration reaches a level above 0.04 M, [See also D. O. Cooke, React. Kinet. Catal. Lett. 3 (1975) 377],... 

Phosphoric and sulfuric acid derivatives possess crucial properties that allow them to uniquely fill their many roles in biochemistry. Phosphoric acid may be esterified to form a monoester, diester, or triester (Figure 1). Sulfuric acid may be esterified at one or two positions, to form a monoester or a diester. Sulfate diesters are highly reactive, and have not been found in nature nor do phosphate triesters occur naturally. The hydrolysis of both phosphate and sulfate esters are thermodynamically favorable, but nucleophiles are repelled by the negative charge of the ionized forms. The resulting kinetic stability of phosphate monoesters and diesters, and of sulfate monoesters, is a major factor in their suitability for biological roles. For example, the half-life for hydrolysis of alkyl phosphate dianions by water is approximately 1.1 X 10 years k=2 x 10 s ) at 25°C. Such species... 

Compounds of these types are not covered in the I.U.C. rules. In substantial agreement with Chemical Abstracts usage many of these compounds can be named as amido ( —NH2), imido (/NH), and nitrido (instead of the more usual nitrilo for N) substitution derivatives of the oxygen acids (ammono- and ammonoaquophosphoric, -phosphorous, and -sulfuric acids) -J... 

The acid chemicals like nitric, phosphoric and sulfuric acid used in this study were of analytical grades and supplied by Panreac Company. C02 gas of 99.999% purity and natural gas containing 100 ppm H2S were provided by Saudi Gas Company. All glass wares were of Pyrex, washed with demineralized water and dried in an oven at 105°C. 

The third reactor provides for final ammoniation of overflow from the second reactor. Phosphoric and sulfuric acids are added and the KCl dissolved (when NPK is produced). 

Whilst solid acids such as zeolites and other aluminosilicates have been the subject of considerable study in the context of alkane chemistry (e.g. catalytic cracking and alkene isomerisation), the design of more versatile materials which can be used in the fine chemical industry has been less thoroughly researched. However, the need for the production of solid acids to replace traditional protonic acids such as hydrogen fluoride, phosphoric and sulfuric acids in liquid phase processes is an increasingly important goal. Some progress has been made in this area and the commercial product Envirocat EPIC [19] provides an excellent example of a... 

Phosphoric and sulfuric acids are corrosive. Do not allow either acid to touch your skin. 

GlipaX, Bonnet B, Mula B et al (1999) Investigation of the conduction properties of phosphoric and sulfuric acid doped polybenzimidazole. J Mater Chem 9 3045-3049... 

Zirconium is a reactive metal that relies on an oxide film for corrosion protection. It can be used in nitric, hydrochloric, phosphoric, and sulfuric acids (the last two have a concentration threshold above which zirconium is not recommended). Zirconium is prone to chloride-induced pitting corrosion in the presence of oxidizing species such a ferric ions. 

Alloy X has excellent resistance to nitric acid, organic acids, alkalies, salts, seawater, chloride cracking, and good to excellent resistance to phosphoric and sulfuric acids, with good resistance in hydrochloric and hydrofluoric acids. 

Alloy G resists pitting, crevice corrosion, and intergranular corrosion. Applications include heat exchangers, pollution control equipment, and various applications in the manufacture of phosphoric and sulfuric acids. 

The final group of copper alloys are the copper-nickel (cupronickels) alloys. They exhibit the best resistance to corrosion, impingement, and SCC of all the copper alloys. They are among the best alloys for seawater service and are immune to season cracking. Dilute hydrochloric, phosphoric, and sulfuric acids can be handled. They are almost as resistant as Monel to caustic soda. 

Complex fertilizers containing much sulfate sulfur possess increased agrochemical activity. Production of these fertilizers is based on neutralizing a mixture of phosphoric and sulfuric acids by ammonium and obtaining... 

Strong inorganic acids, such as hydrochloric, phosphoric and sulfuric acid, may not be added to... 

Hie practical disadvantage of the dirert SSP is the inevitable SMT occurring whenever the reaction proceeds at reasonable rates (Section 4.34.2.2). To overcome this problem, catalysts have been used to increase the reaction rate and favor keeping the process in the solid state. Boric, phosphoric, and sulfuric acids were studied as catalysts for the SSP of PA salts.The results showed a considerable acceleration of the reaction, especially in the presence of boric acid, while the solid character of the process was maintained throughout the total course of the reaction, keeping the water accumulation parameter (Dp eqn [4]) at low values (Figure 6) ... 

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