Stable carbonium ions. XXXI. p-Anisonium and methylphenonium ion-formation via aryl participation in strong acid solution

1967 ◽  
Vol 89 (20) ◽  
pp. 5259-5265 ◽  
Author(s):  
George A. Olah ◽  
Melvin B. Comisarow ◽  
Eli. Namanworth ◽  
Brian G. Ramsey
Keyword(s):  
Acid Solution ◽  
Strong Acid ◽  
Ion Formation ◽  
Carbonium Ions ◽  
Aryl Participation

Isobutane from acid-catalyzed dehydration of butanols

1970 ◽  
Vol 48 (22) ◽  
pp. 3545-3548 ◽  
Author(s):  
John Warkentin ◽  
Kenneth E. Hine
Keyword(s):  
Acid Solution ◽  
Hydride Transfer ◽  
Strong Acid ◽  
Isomeric Butanols ◽  
Carbonium Ions ◽  
Acid Catalyzed

Dehydration of the four isomeric butanols by strong acid at about 160° gives a C4-fraction containing isobutane as well as the isomeric butenes. Isobutane probably arises by hydride transfer, from one or more donors including the substrate alcohol and hydrocarbons formed from it in the medium, to one or more carbonium ions including the t-butyl cation. Materials which react with 2,4-dinitrophenylhydrazine reagent to form 2,4-dinitrophenylhydrazones can be swept out of the hot acid solution with a stream of nitrogen.

scholarly journals Resíduo de mármore como atenuador de efluente ácido

2019 ◽  
Vol 19 (1) ◽  
pp. 33-42
Author(s):  
Mirna Aparecida Neves ◽  
Simone Pereira Taguchi ◽  
Douglas Rosa da Silva ◽  
Fabrício Thiengo Vieira
Keyword(s):  
Acid Solution ◽  
Fine Particles ◽  
Strong Acid ◽  
Magnesium Carbonate ◽  
Open Pit ◽  
Dimension Stone ◽  
Environmental Legislation ◽  
Liquid Phases ◽  
Stone Industry ◽  
Marble Waste

Dimension stones are worldwide used as building and finishing material, reason why the environmental problems inherent to this productive sector became relevant in various countries. One of these problems is the production of large amounts of wastes during the sawing of rocky blocks and polishing of plates. The waste generated by cutting marble with diamond wire consists of fine particles of calcium and magnesium carbonate dispersed in water. This mud has basic character, and it is destined to drying beds or open pit deposits. In parallel, many production processes generate hazardous acidic effluents, which disposal is a serious and global problem. The pH of these solutions must be neutralized or, at least, raised to levels that are considered safe by environmental regulations. In this work, a strong acid solution was treated with varying amounts of marble waste coming from the dimension stone industry. The treatment generated secondary solid and liquid phases that were analyzed to determine the feasibility of their disposal in landfills. The waste raised the pH of the acid solution from near 1.0 to values between 5.0 and 6.0, which are acceptable levels for non-dangerous effluents. Besides that, loss of up to 50% in mass occurred, diminishing the amount of the primary solid waste. By the other hand, the levels of total dissolved solids (TDS), Cu, chlorides and nitrates on the liquid phase of the effluent remained higher than that allowed by environmental legislation for discharge into water bodies. Nevertheless, their characteristics correspond to non-hazardous and non-inert wastes, which, after dried, can be discarded in ordinary waste landfills.

scholarly journals Kinetic determination of As(III) in solution

2003 ◽  
Vol 68 (10) ◽  
pp. 765-769
Author(s):  
Sofija Rancic ◽  
Rangel Igov ◽  
Todor Pecev
Keyword(s):  
Acid Solution ◽  
Relative Error ◽  
Reaction Rate ◽  
Kinetic Method ◽  
Kinetic Equations ◽  
Strong Acid ◽  
Kinetic Determination

A new reaction is suggested and a new kinetic method is elaborated for the As(HI) traces determination in solution, on the basis of their catalyzing effect on komplexon III (EDTA) oxidation by KMnO4 in a strong acid solution (H2SO4). Using a spectrophotometric technique, a sensitivity of 72 ng/cm3 As(IIl) was achieved. The relative error of method varies from 5.5 to 13.9 % for As(HT) concentration range from 83 to 140 ng/cm-1. Appropriate kinetic equations are formulated and the influence of some other ions, including the As(V), upon the reaction rate is tested.

Mechanistic studies in strong acids. VIII. Hydrolysis mechanisms for some thiobenzoic acids and esters in aqueous sulfuric acid, determined using the excess acidity method

1982 ◽  
Vol 60 (24) ◽  
pp. 3061-3070 ◽  
Author(s):  
Robin A. Cox ◽  
Keith Yates
Keyword(s):  
Sulfuric Acid ◽  
Proton Transfer ◽  
Strong Acid ◽  
Weak Acid ◽  
Medium Composition ◽  
Hydrolysis Rate ◽  
Water Molecules ◽  
Aqueous Sulfuric Acid ◽  
Ion Formation ◽  
Rate Determining Step

The excess acidity method has been applied to hydrolysis rate data, obtained as a function of medium composition, for four thiobenzoic acids, thioacetic acid, eight ethyl thiolbenzoates, and eight ethyl thionbenzoates in aqueous sulfuric acid. The mechanistic behaviour thus revealed has both similarities to and differences from that of a typical ester like ethyl benzoate, which gives benzoic acid by an A-2 reaction involving two water molecules in weak acid, and by A-1 acylium ion formation in strong acid. The thioacids follow this behaviour, except that the A-2 process involves three water molecules, and that the mechanistic changeover occurs in 60% rather than 80% acid. The A-2 process for the ethyl thiolbenzoates is slow; the major hydrolysis mechanism is acylium ion formation, not in an A-1 reaction but by a concerted A-SE2 process involving both proton transfer to sulfur and carbon–sulfur bond breaking. The major proton transfer agent is the undissociated sulfuric acid molecule. The thionbenzoate esters, in contrast, undergo very fast A-2 hydrolysis; so fast, in fact, that the initial protonation of sulfur is the rate-determining step in acids more dilute than about 62% w/w. It appears that proton transfer to sulfur is a comparatively slow process.

Treatment of Spent Acidic Decontaminants With a High-Efficiency Cementation Method

2011 ◽  
Author(s):  
Kou-Ming Lin ◽  
Ching-Tu Chang ◽  
Ming-Shin Wu ◽  
Wen-Chen Lee ◽  
Jen-Chieh Chung ◽  
...  
Keyword(s):  
Phosphoric Acid ◽  
Acid Solution ◽  
High Efficiency ◽  
Strong Acid ◽  
Energy Research ◽  
Nuclear Facilities ◽  
Chemical Decontamination ◽  
Radioactive Nuclides ◽  
Excellent Method ◽  
Regulatory Procedure

Metal scrap is a major waste generated from the decommissioning of nuclear facilities. Through a decontamination process, most of the metal scraps can be cleaned to meet the clearance levels, which can then be reused or released according to the regulatory procedure. Usually, chemical processes will be used in the cleaning step. Phosphoric acid and fluoroboric acid are the typical chemicals used for decontamination. Although the decontaminant could be reused multiple times after regeneration, its decontamination efficiency would decrease after 3 to 5 cycles. In addition, the radioactive nuclides such as Cs-137 are not easily removed during the regeneration process; it tends to accumulate slowly in the decontaminant. According to the ALARA principle, decontaminant must be replaced if its radioactive activity exceeds the regulatory levels. As a result, a significant amount of spent strong acid solution would be generated. The conventional way of treatment is to neutralize the acid solution with an alkaline solution. However, such method will produce a large amount of sludge that requires further stabilization, which offsets the advantages of metal decontamination by use of the decontaminant. A high-efficiency solidification method has been developed and used to treat the spent phosphoric acid and fluoroboric acid solution in Institute of Nuclear Energy Research (INER). The self-polymerization nature of highly concentrated phosphoric acid is adopted to immobilize the radioactive nuclides. The volume of solidified form is almost equal to that of the treated acid solution. The waste form demonstrates its quality by compression test and leaching test. This cementation process is an excellent method to minimize the secondary waste, which is generated from chemical decontamination for treating metal waste.

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