Hydrofluoric acid reaction products

A basic step in hydrofluoric acid manufacture is the reaction of sulfuric acid with fluorspar (calcium fluoride) to produce hydrogen fluoride and calcium sulfate. Spent alumina is also generated by the defluorination of some hydrofluoric acid alkylation products over alumina. It is disposed of or sent to the alumina supplier for recovery. Other solid residuals from hydrofluoric acid alkylation include any porous materials that may have come in contact with the hydrofluoric acid. 

N. Tschischewsky made the nitride by working at 1400°. About 4 per cent, of the silicon volatilizes during the reaction. The product obtained after heating the silicon in nitrogen for an hour is an amorphous, voluminous, white powder which, under the microscope, seems to consist of several different substances. The composition of the final product is dependent on the mode of purification if boiled with potassium hydroxide soln., followed by treatment with hydrofluoric acid, a product containing silicon hemitrinitride mixed with silica is obtained. The silica could not be removed from the nitride. M. Blix and W. Wirbelauer obtained the nitride by heating silicam, Si2N3H, between 1200° and 1400° and H. St. C. Deville and F. Wohler, by the action of ammonia on silicon chloride. 

Stannous fluoride probably was first prepared by Scheele in 1771 and was described by Gay-Lussac and Thenard in 1809. Commercial production of stannous fluoride is by the reaction of stannous oxide and aqueous hydrofluoric acid, or metallic tin and anhydrous hydrogen fluoride (5,6). Snp2 is also produced by the reaction of tin metal, HP, and a halogen in the presence of a nitrile (7). 

Titanium trifluoride is prepared by dissolving titanium metal in hydrofluoric acid (1,2) or by passing anhydrous hydrogen fluoride over titanium trihydrate at 700°C or over heated titanium powder (3). Reaction of titanium trichloride and anhydrous hydrogen fluoride at room temperature yields a cmde product that can be purified by sublimation under high vacuum at 930—950°C. 

Fluorogypsum is the name ascribed to by-product gypsum from fluorspar acidulation to produce hydrofluoric acid. The chemical reaction... 

The principal use of the alkylation process is the production of high octane aviation and motor gasoline blending stocks by the chemical addition of C2, C3, C4, or C5 olefins or mixtures of these olefins to an iso-paraffin, usually isobutane. Alkylation of benzene with olefins to produce styrene, cumene, and detergent alkylate are petrochemical processes. The alkylation reaction can be promoted by concentrated sulfuric acid, hydrofluoric acid, aluminum chloride, or boron fluoride at low temperatures. Thermal alkylation is possible at high temperatures and very high pressures. 

Almost all of the biomedical research done in the 25 years following the liquid-breathing work was conducted with commercially available fluorocarbons manufactured for various industnal uses by the electrochemical Simons process (fluonnation in a hydrofluoric acid solution) or the cobalt fluoride process (fluori-nation with this solid in a furnace at about 200 C) These processes tended to yield many by-products, partly because they were, to some extent, free radical reactions and partly because it was difficult to easily achieve complete fluonnation Aromatic hydrocarbons gave better products with the cobalt tnfluonde [73] method, whereas saturated hydrocarbons yielded better products with fluonnation using diluted or cooled gaseous fluorine (Lagow) Incompletely fluormated matenal was either... 

The LAB production process (process 1) is mainly developed and licensed by UOP. The N-paraffins are partially converted to internal /z-olefins by a catalytic dehydrogenation. The resulting mixture of /z-paraffins and n-olefins is selectively hydrogenated to reduce diolefins and then fed into an alkylation reactor, together with an excess benzene and with concentrated hydrofluoric acid (HF) which acts as the catalyst in a Friedel-Crafts reaction. In successive sections of the plant the HF, benzene, and unconverted /z-paraffins are recovered and recycled to the previous reaction stages. In the final stage of distillation, the LAB is separated from the heavy alkylates. 

H.13 Hydrofluoric acid is used to etch grooves in glass because it reacts with the silica, Si02(s), in glass. The products of the reaction are aqueous silicon tetrafluoride and water. Write a balanced equation for the reaction. 

Chromate conversion coatings for aluminum are carried out in acidic solutions. These solutions usually contain one chromium salt, such as sodium chromate or chromic acid and a strong oxidizing agent such as hydrofluoric acid or nitric acid. The final film usually contains both products and reactants and water of hydration. Chromate films are formed by the chemical reaction of hexavalent chromium with a metal surface in the presence of accelerators such as cyanides, acetates, formates, sulfates, chlorides, fluorides, nitrates, phosphates, and sulfamates. 

Mineral acids include hydrochloric acid and blends of hydrochloric and hydrofluoric acid (usually 12% HCl/3% HF). Hydrochloric acid is used to acidize carbonate formations. Its advantages are relatively low cost, high carbonate mineral dissolving power, and the formation of soluble reaction products (which minimizes formation damage). The primary disadvantage of hydrochloric acid is its corrosive nature. 

The reaction of 1 with hydrobromic acid gave quantitatively the cis adduct 14 (Scheme 11). The reaction of 1 with hydrochloric acid gave the cis adduct 15 in 79% yield and the trans adduct 16 in 18% yield. In these reactions, no other Si-Si bond cleavage products were obtained. The ladder polysilane 1 did not react with hydrofluoric acid. The reactions of 1,4-di-ter -butyl-2,2,3,3,5,5,6,6-octaisopropylbicyclo[2.2.0]hexasilane with hydrobromic acid and hydrochloric acid were attempted, but no reactions took place. This result is ascribed to steric hindrance by the tert-butyl groups on the bridgehead silicon atoms. 

With hydrofluoric acid (23,50), and to a lesser degree also with zeolites (14,81, 87-89), a significant fraction of the product stems from self-alkylation, which is sometimes also termed hydrogen transfer. The importance of this mechanism depends on the acid, the alkene, and the reaction temperature. Self-alkylation... 

Deacylation [16], hydrolysis with 47% aqueous hydrofluoric acid (HF) and phase partition of the reaction products [1], and acetolysis [17] were performed as described in the literature. 

After the reaction is completed the products can be poured into water and ice and the aqueous hydrofluoric acid disposed of down the drain. Care must again be exercised as the mixing of hydrogen fluoride and water generates considerable heat. No hazards or disposal difficulties are incurred with hydrofluoric acid in the usual drain lines as these are made of iron pipe and the hydrogen fluoride is soon absorbed as firm complexes with the iron. It is not detectable at any great distance from the source. For some reactions this simple form of disposal is not satisfactory, for example, in the preparation of an acyl halide or other product which reacts with water. Here distillation of the hydrogen fluoride... 

While cobalt(II) fluoride is the product of the reaction of anhydrous cobalt(ll) chloride with hydrofluoric acid, cobalt(lll) fluoride is obtained from fluorina-tion of an aqueous solution of cobalt(ll) chloride. 

Reaction with water is complex, producing hydrofluoric acid and oxygen as the main products ... 

During the processing of fuels, acids can be used as extracting/neutralizing agents as well as reaction catalysts. For example, sulfuric acid can be used to remove olefins from fuel. Sulfuric/hydrofluoric acids are used as reaction catalysts in the production of high-octane gasoline alkylate fractions. 

Both gas and liquid are very sol in water. Can be prepd by distUlation from the product of reaction of Ca fluoride (fluorspar) and sulfuric acid. Used as fluorinating agent in organic and inorganic reactions production of fluorine and A1 fluoride prepn of hydrofluoric acid production of fluoroborates, fluorosilicates, etc as an additive in liquid rocket propellants and for refining of uranium (Ref 3, p 588-R)... 

Like ldpe, polybutadienes are resistant to most nonoxidizing acids, alkalis, and salts. However, because they are unsaturated, the polyalkadienes are attacked by hydrochloric, hydrobromic, and hydrofluoric acids, as well as by hydrogen and chlorine. The reaction products, which are thermoplastic, have been used as commercial nonelastomcric plastics. NR and other diene elastomers are also attacked by peroxides and ozone. In the absence of an tioxidants and carbon black filler, these unsaturated elastomers are degraded in the sunlight. 

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