Results 251 to 260 of about 196,806 (297)

T. C. in acidic media

Journal of Labelled Compounds, 1970
AbstractTritium labelling of aromatic compounds in a few acidic media and the intramolecular distributions of radioactivities in the tritiated compounds were investigated. Various kinds of aromatic compounds were treated with powerful acid complex, TH2PO4.BF3, or some other tritiated acids at room temperature.
Masayuki Hamada, Reiko Kiritani
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Pyrrhotite dissolution in acidic media

Applied Geochemistry, 2014
Abstract Non-oxidative dissolution rates for hexagonal pyrrhotite (Fe1−xS) were measured for pH values ranging from 0 to 1.3 and temperatures ranging from 25 to 70 °C. These results showed that pyrrhotite dissolution rate increases with decreasing pH or increasing temperature.
Paul Chiriţă, J. Donald Rimstidt
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Chemistry of sulphenates in acidic media

Journal of the Chemical Society, Perkin Transactions 2, 1978
Methyl toluene-p-sulphenate is hydrolysed rapidly in moist solvents (dioxan, benzene, chloroform, or nitrobenzene) yielding methyl toluene-p-sulphinate, di-p-tolyl disulphide, and methanol. The reaction is acid catalysed. At higher concentration of water (>1%) the products are: p-tolyl toluene-p-thiolsulphonate, di-p-tolyl disulphide, and methanol.
Ennio Ciuffarin, Sandro Gambarotta, Mauro Isola, Lucio Senatore   +3 more
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Pyrite dissolution in acidic media

Geochimica et Cosmochimica Acta, 2004
Oxidation of pyrite in aqueous solutions in contact with air (oxygen 20%) was studied at 25°C using short-term batch experiments. Fe2+ and SO42− were the only dissolved Fe and S species detected in these solutions. After a short period, R = [S]tot/[Fe]tot stabilized from 1.25 at pH = 1.5 to 1.6 at pH = 3. These R values were found to be consistent with
Descostes, M., Vitorge, P., Beaucaire, C.   +2 more
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Pentafluorophenyliminothiodihalides and their conversions in acid media

Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, 1979
1. Pentafluorophenyliminothiodifluoride is formed upon the action of SF4 on pentafluoroaniline in the presence of NaF. A new group of unsymmetrical thiodiimides, containing the pentafluorophenyl ring, is synthesized. 2.
A. V. Zibarev, I. R. Gol'ding, A. M. Sladkov, G. G. Furin, G. G. Yakobson   +4 more
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Hydroxamic Acids as Weak Base Indicators:  Protonation in Strong Acid Media

The Journal of Organic Chemistry, 2001
The protonation equilibria of N-phenylbenzohydroxamic, benzohydroxamic, salicylhydroxamic, and N-p-tolylcinnamohydroxamic acids have been studied at 25 degrees C in concentrated sulfuric, hydrochloric, and perchloric acid media; the UV-vis spectral measurements were analyzed using the Hammett equation and the Bunnett-Olsen and excess acidity methods ...
B. GARCIA, S. IBEAS, F. J. HOYUELOS, J. M. LEAL, SECCO, FERNANDO, VENTURINI, MARCELLA   +5 more
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Acidities of strong neutral Brønsted acids in different media

Journal of Physical Organic Chemistry, 2012
Acidities of different families of acids are examined in media of different physical and chemical nature: water, acetonitrile (AN), 1,2‐dichloroethane (DCE) and the gas phase, with special emphasis on strong acids. Included are OH (carboxylic acids, alcohols, and phenols), NH (sulfonamides, imides), and CH (phenylmalononitriles, etc.) acids as well as ...
Elin Raamat, Karl Kaupmees, Gea Ovsjannikov, Aleksander Trummal, Agnes Kütt, Jaan Saame, Ivar Koppel, Ivari Kaljurand, Lauri Lipping, Toomas Rodima, Viljar Pihl, Ilmar A. Koppel, Ivo Leito   +12 more
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Applicability of excess acidity functions in low‐acidity media

Journal of Physical Organic Chemistry, 1991
AbstractIt is demonstrated that excess acidity functions do not correspond well to the pH scale in dilute solutions. Acidity constants, pK, of seven moderately weak bases were determined; they were calculated by means of excess acidity functions, since the corresponding ionizations occur at acidity levels where the pH scale is partly used.
Begoña García, José M. Leal
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Reactions of Mixed Natural Acids and Esters in Acidic Media

2023
Citric acid and malic acid are renewable organic acids with considerable market size. The reaction between the two acids in sulfuric acid at 80 °C gave an unexpected pyrone diacid. A mixture of dimethyl malate and trimethyl citrate gave a pyrone diester. These pyrones were produced in good yields on a multigram scale.
William J. Bradley, Yang Qu, Zachery Crandall, Theresa L. Windus, George A. Kraus   +4 more
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Acidity level in concentrated mineral acid mixtures. Iso-acidic media

Canadian Journal of Chemistry, 1987
Assuming the relationship between the R0(H) acidity function and the water activity in mineral acid concentrated solutions, iso-acidic solutions are prepared by mixing in all proportion two or three of the acids: H3PO4, HCl, HClO4, H2SO4, H2SiF6. These solutions are characterized by an equal R0(H) acidity level and different redox and complexing ...
C. Louis, A. Bebba, J. Bessiere
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