Kinetics of oxidation and dissolution of uranium dioxide in aqueous acid solutions

2012 ◽  
Vol 83 ◽  
pp. 471-477 ◽  
Author(s):  
Coralie Gaulard-Balandret ◽  
Nathalie Larabi-Gruet ◽  
Frédéric Miserque ◽  
Jean Radwan ◽  
Cécile Ferry ◽  
...  
Keyword(s):  
Uranium Dioxide ◽  
Acid Solutions ◽  
Kinetics Of Oxidation ◽  
Aqueous Acid ◽  
Kinetics Of

A Study of Substituent Effect on the Oxidative Strengths of N-Chloroarenesulphonamides: Kinetics of Oxidation of Leucine and Isoleucine in Aqueous Acid Medium

2004 ◽  
Vol 59 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Mahesha Shetty ◽  
B. Thimme Gowda
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Ionic Strength ◽  
Acid Medium ◽  
Benzene Ring ◽  
Thermodynamic Data ◽  
Substituent Effect ◽  
Kinetics Of Oxidation ◽  
Aqueous Acid ◽  
Kinetics Of

Abstract To study the variation of oxidative strengths of N-chloro-arenesulphonamides with substitution in the benzene ring, six mono- and five di-substituted N-chloro-arenesulphonamides are employed as oxidants for studying the kinetics of oxidation of two neutral amino acids, L-leucine and Lisoleucine in aqueous acid medium. The N-chloro-arenesulphonamides studied are of the constitution: ArSO2NaNCl·H2O (where Ar = C6H5, 4-CH3C6H4, 4-C2H5C6H4, 4-FC6H4, 4-ClC6H4, 4-BrC6H4, 2,3-(CH3)2C6H3, 2,4-(CH3)2C6H3, 2-CH3-4-ClC6H3, 2,4-Cl2C6H3, and 3,4-Cl2C6H3). The reactions show second order kinetics in [oxidant], fractional order in [amino acid] and inverse dependence on [H+]. Addition of the reduced product of the oxidants or variation in ionic strength of the medium has no significant effect on the rates of oxidations. A two-pathway mechanism is considered to explain the experimental results. Effective oxidizing species of the oxidants is Cl+ in different forms. Therefore the oxidising strengths of N-chloro-arenesulphonamides depend on the ease with which Cl+ is released from them. The study reveals that the introduction of substituent in the benzene ring of the oxidant affects both the kinetic and thermodynamic data for the oxidations The electron releasing groups such as CH3 generally inhibit the rates, while electron-withdrawing groups such as Cl enhance this ability, as the electron withdrawing groups ease the release of Cl+ from the reagents and hence increase the oxidising strengths. The on Ea and logA and validity of the Hammett and isokinetic relationships for the oxidations are also analysed.

Kinetics of the dissociation of tris(1,10-phenanthroline) iron(III) complex ion in aqueous acid solutions. A mechanistic model for product specificity

1993 ◽  
Vol 18 (2) ◽  
pp. 231-237 ◽  
Author(s):  
Kambhampati Sriramam ◽  
Brahmandam S. R. Sarma ◽  
Konidena Kalidas ◽  
Janapati Sreelakshmi ◽  
Chintalapudi Ramakrishna
Keyword(s):  
Mechanistic Model ◽  
Acid Solutions ◽  
Product Specificity ◽  
Aqueous Acid ◽  
Kinetics Of ◽  
Complex Ion

Kinetics of oxidation of nitrite by aqueous chlorine

1973 ◽  
Vol 26 (9) ◽  
pp. 1857 ◽  
Author(s):  
JN Pendlebury ◽  
RH Smith
Keyword(s):  
Nitrous Acid ◽  
Ionization Constant ◽  
Initial Step ◽  
The Other ◽  
Stopped Flow ◽  
Unimolecular Decomposition ◽  
Solution Ph ◽  
Kinetics Of Oxidation ◽  
Aqueous Acid ◽  
Kinetics Of

The kinetics of oxidation of nitrite to nitrate by chlorine in aqueous acid solution (pH 0-1) have been studied using a spectrophotometric stopped flow technique. The rate law is ���������������� -d[Cl2]a/dt =([Cl2][NO2-]/Ka[Cl-]2)(f+g[HNO2]) where [Cl2]a = [Cl2]+[Cl3-] and where Ka is the ionization constant for nitrous acid. At 298.2 K and ionic strength 2.75M, f = 60.8�0.5 mol2 l-2 s-1 and g = (2.35�0.05)x105 mol l-1 s-1: the associated activation energies are 68�3 and 44�2 kJ mol-1 respectively. A mechanism is proposed involving the reversible initial step: �������������������������� NO2-+Cl2 ↔ NO2Cl+Cl- with the NO2Cl undergoing two parallel subsequent reactions, one a unimolecular decomposition and the other an attack by HNO2 upon NO2Cl. ��� Oxidation of nitrite by the three halogens, Cl2, Br2, I2, is discussed.

Reactions of Ethylene with Rhodium (III) Chloride. Part III. The Catalytic Oxidation of Ethylene to Acetaldehyde in Aqueous Hydrochloric Acid Solutions Containing Pentachloroaquorhodate(III)

1972 ◽  
Vol 50 (11) ◽  
pp. 1698-1707 ◽  
Author(s):  
B. R. James ◽  
M. Kastner
Keyword(s):  
Hydrochloric Acid ◽  
Acid Chloride ◽  
Rate Constants ◽  
Acid Solutions ◽  
Reaction Conditions ◽  
Gas Uptake ◽  
Mild Conditions ◽  
Aqueous Acid ◽  
Hydrochloric Acid Solutions ◽  
Kinetics Of

In the presence of iron(III) or other oxidants, aqueous acid chloride solutions of RhCl5(H2O)2− catalyze under mild conditions the oxidation of ethylene to acetaldehyde. The kinetics of the reaction measured by gas-uptake techniques indicate the presence of both ethylene dependent and independent paths. Besides fully protonated anions, hydroxy species such as RhCl5 (OH)3− and RhCl4(OH)(H2O)2−, although present in very small concentrations, are significantly reactive towards ethylene. A mechanism, based on that postulated for a similar palladium(II) system in the well-known Wacker process, is presented. Under our reaction conditions the slow steps in the rhodium system involve formation of π-complexes in the ethylene dependent paths and the formation of tetrachlororhodate(III) complexes in the ethylene independent paths. Iron(III) regenerates the rhodium(III) catalyst by oxidation of the rhodium(I). Rate constants are estimated for the various reaction paths.

scholarly journals Kinetics of aniline polymerization initiated with iron(III) chloride

2006 ◽  
Vol 71 (8-9) ◽  
pp. 895-904 ◽  
Author(s):  
Gordana Nestorovic ◽  
Katarina Jeremic ◽  
Slobodan Jovanovic
Keyword(s):  
Polymerization Reaction ◽  
Side Reactions ◽  
Integer Number ◽  
Acid Solutions ◽  
Initial Concentration ◽  
Aqueous Acid ◽  
Theoretical Yield ◽  
Faraday Law ◽  
Kinetics Of ◽  
Aniline Polymerization

The reaction kinetics of the chemical polymerization of aniline in aqueous acid solutions with FeCl3 as the oxidant (initiator) was investigated at 25?C. The polymerization was performed in a special reactor which enabled the initial concentration of oxidant to be kept constant during the polymerization reaction. The order of the reaction of ANI polymerization with respect to FeCl3 was calculated as n=0.18. The rate constant k of the polymerization reaction was found to be 9.1x10-5(mol dm-3)-1,18 s-1. The theoretical yield of the reaction was calculated using the Faraday law and the experimentally determined quantity of electricity exchanged during the polymerization reaction. There was a discrepancy between the experimentally and theoretically determined yield, indicating that the oxidant was being consumed in some side reactions, which is an accordance with the fact that the order of the reaction of ANI polymerization with respect to FeCl3 is a non-integer number.

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