Reaction Of Bromate Research Articles

Kinetic scheme of oscillation reaction of three and four particles

The paper deals with four schemes, each of three out of the particles X, A, Y, C, consisting of two coupled autocatalytic blocks of the type Q→X→A→Y→C. The schemes showing relative stability of the Y particle or its dimer can exhibit a limit cycle, the other have always a stable stationary point. The scheme of four particles X, A, Y, C or dimers of particles X, Y can exhibit an unstable stationary point with the limit cycle. For the individual cases conditions were derived for the rate constants sufficient for formation of the limit cycle, and they are discussed from the point of view of available experimental data on the reaction of bromate with phenol and aniline.

Flow-injection spectrophotometric determination of trace vanadium based on catalysis of the gallic acid bromate reaction

High sensitivity is obtained by using high concentrations of gallic acid and bromate, although the uncatalyzed reaction is significant. Various reactant concentrations, reaction temperature, pH and residence times can be used to alter the linear calibration ranges and sensitivity for vanadium. With reagent streams of 1.76 M bromate and 0.06 M gallic acid at pH 3.8 (each at 1 ml min −1), 0.2–20 ng of vanadium (20-μl injections) can be determined at 30°C. Oxidized gallic acid is detected at 380 nm. When the bromate concentration is decreased to 0.5 M and the temperature is 65°C, 0.05–4 ng of vanadium can be determined; the relative standard deviation is ca. 5% for 0.6 ng of vanadium. The toleranes for Al(III), Fe(III), Mo(VI) and iodide are 10 ng, 10 ng, 50 ng and 200 ng, respectively, for the determination of 1 ng of vanadium. About 12 samples can be injected per hour.

Periodic Operation of a Stirred Flow Reactor with Limit Cycle Oscillations

AbstractThe oscillating flow reaction of bromate, bromide, and cerous ions was investigated computationally in a continuously stirred tank reactor (CSTR) where periodic perturbations were imposed on either the input rate or one of the inflow concentrations. The model computations predict a variety of interesting phenomena such as harmonic and subharmonic entrainment, chaos, transient behavior, and low amplitude harmonics. Under certain conditions the natural oscillations of the system can be considerably damped or enhanced by perturbation inputs of the proper frequency. The theoretical behavior of the system, studied under various experimental conditions, suggests many feasible experiments which are interesting in themselves, but may also serve as an additional probe of the complex mechanism used.

Determination of Potassium Bromate in Foods by High Performance Liquid Chromatography

A method was developed for the determination of bromate in bread and fish paste products by high performance liquid chromatography (HPLC) with a post-column derivatization procedure based on the formation of triiodide ion by the reaction of bromate and iodide.Bromate was extracted with water from samples. The extract was cleaned up by the use of a Bond Elut SAX column (perchlorate form) with 0.04M sodium perchlorate solution (pH 3.5, perchloric acid) as an eluent. Bromate was separated on a column packed with Zorbax SAX by using 0.04M sodium perchlorate solution (pH 3.5, perchloric acid) as a mobile phase, with detection at 350nm.The calibration curve was linear in the range from 2.5ng to 50ng. The recoveries were 79.0-87.3% from bread and 75.6-81.3% from fish paste products. The detection limit was 0.05ppm.

Formation of BrO2 in the Belousov-Zhabotinsky-System Reaction of Aliphatic Alcohols with Bromate

BrO2 was found as an intermediate in the reaction of bromate with alcohols (e.g. methanol, isopropanol, allylalcohol) or ketones (e.g. acetone). This reaction may be important for the understanding of bromate driven oscillators.

Study of the mechanism of the oscillating reaction between bromate and phenol

In the oscillating reaction of bromate with phenol in the medium of 0.4M-H2SO4, the length of the induction period is governed by a kinetic equation for a second-order reaction with a stoichiometry 1 : 1. The concentration of quinones in the reaction mixture increases also according to a kinetic equation for a second-order reaction. The influence of various compounds is discussed, whose additions shorten or prolong the induction period, bring about oscillations in a nonoscillating reaction mixture, or change the frequency of these oscillations. From the comparison of the time dependences of the potential of a platinum and an ion-selective electrodes and of the limiting current of the quinones, a reaction mechanism was proposed.

Flow injection determination of trace vanadium with catalytic photometric detection

A catalytic photometric detection system based on the chromotropic acid—bromate reaction is adapted to a flow injection system for the rapid, simple and sensitive determination of vanadium. Vanadium in the range 0.3–4.8 ng (10–160 ppb) can be determined at a rate of ca. 60 samples per hour.

A new catalytic method for the determination of vanadium

A new catalytic method for the determination of 0–0.6 ppm of vanadium is described. The method is based on the catalytic action of vanadium on the reaction of bromate with bromide at pH = 1.80 ± 0.05. In this hitherto unreported reaction no bromine is formed, but in a two-step process hypobromite is produced. The rate is monitored by potentiometry, and results are evaluated from the recorded potential vs time curves. The optimal conditions for the determination have been investigated, and interferences as well as their elimination studied. The stoichiometry, mechanism, and kinetics of both the uncatalyzed and the catalyzed reactions were investigated, and the rate constants (for 20 °C) and the entropies and enthalpies of activation of both the uncatalyzed and the catalyzed reactions were determined.

A modified Oregonator model exhibiting complicated limit cycle behavior in a flow system

A reversible Oregonator model has been used to simulate recent experimental measurements by Schmitz, Graziani, and Hudson of complicated oscillations by a Belousov–Zhabotinsky system in a stirred tank reactor. The experimental observations indicate chaotic behavior of the small amplitude oscillations occurring between major excursions, but our computer simulation with a small error parameter apparently generates a true limit cycle with six relative maxima before the pattern repeats. The differences between experiment and simulation suggest the chaotic behavior observed experimentally may result from fluctuations too small to measure in any other way. The computations also indicate that reversibility of the reaction of bromate with bromide is important in a continuously stirred tank reactor under conditions such that the (unstable) steady state has a very low concentration of bromide ion.

Measurement of homogeneous reaction rate by concentration-step, controlled potential electrolysis

A concentration-step method was introduced to controlled potential coulometry for the study of chemical kinetics and was named concentration-step, controlled potential electrolysis. In this method, an amount of the reaction agent is added to the electrolytic solution which is maintained in a controlled potential condition and the current-time curve is measured. The current-time curve has a peak and the reaction rate is obtained by measuring the time when the current is maximum. To demonstrate the present method the reactions of ethylenediaminetetraacetato-ferrous complex and several oxidizing agents were studied and the pseudo first-order reaction rate constants were evaluated. The optimum range of the measurement was estimated to be 10 −3–10 2 dm 3 mol −1 s −1 and the rate constant of the reaction of potassium bromate and ethylenediaminetetraacetato-ferrous by this method was in fair agreement with that found by polarography.

Chemical Oscillatory Systems—Gallic Acid and Bromate Reaction Catalysed by Ferroin

Chemical Oscillatory Systems—Gallic Acid and Bromate Reaction Catalysed by Ferroin

Catalysis of the arsenic(III)-potassium bromate reaction—II: Catalytic determination of osmium

A simple visual titrimetric procedure is proposed for the catalytic determination of osmium, based on the arsenic(III)-bromate reaction. A detailed kinetic study of the catalytic reaction allows a mechanism to be proposed and optimum conditions for analysis to be selected. The analytical method has a detection limit of 10 −4 ppm osmium and possesses a higher degree of freedom from interference by ruthenium than other similar systems.

Oscillatory Oxidation of Malonic Acid by Bromate 3. CO2 and BrO3 --Titration

Abstract The reaction of malonic acid and bromate in the presence of catalytic amounts of cerious ion under oscillating conditions in sulphuric acid was investigated. After two hours reaction time 26 mM bromate were consumed and 42 mM CO2 produced. No formic acid was detected. Furthermore, 14C-tracer experiments suggest that malonic acid is first brominated and subsequently decarboxylated.

Oscillating reaction. Reaction of potassium bromate, ceric sulfate, and a dicarboxylic acid

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTOscillating reaction. Reaction of potassium bromate, ceric sulfate, and a dicarboxylic acidThomas C. Bruice and George J. KasperekCite this: Inorg. Chem. 1971, 10, 2, 382–386Publication Date (Print):February 1, 1971Publication History Published online1 May 2002Published inissue 1 February 1971https://doi.org/10.1021/ic50096a034RIGHTS & PERMISSIONSArticle Views358Altmetric-Citations64LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (595 KB) Get e-Alerts Get e-Alerts

Molten lithium-potassium nitrate: The reactions of some halogen compounds

The reactions of chloride, bromide and iodide with pure molten lithium-potassium nitrate eutectic, with nitrogen dioxide and with melts containing potassium dichromate and potassium pyrosulphate were investigated. the stoichiometry of the formation of iodine in pure melts and in dichromate melt solutions was determined, tri-iodide ions being shown to be the product in the presence of excess iodide. The reaction of chlorate, bromate and iodate with pure and acidic melts was also investigated. In the pure melt iodate was shown to react with the nitrite produced by thermal decomposition of the nitrate rather than with the nitrate itself. The stoichiometry of this reaction was determined.

Effect of Bromine Derivatives of Malonic Acid on the Oscillating Reaction of Malonic Acid, Cerium Ions and Bromate

WHEN malonic acid, ceric sulphate and potassium bromate are dissolved in dilute sulphuric acid there occurs an oscillating chemical reaction which manifests itself by an oscillation of the light absorption which is caused by ceric ions (317 mµ) and an oscillation of the rate of evolution of carbon dioxide. An oscillation of the potential of a platinum electrode dipped into the solution can also be measured1. Fig. 1 shows the light absorption at 317 mµ as a function of time in a solution of the above mentioned substances. The curve divides itself into four distinct sections: (a) disappearance of ceric ions; (b) reappearance of ceric ions; (c) stationary concentration of ceric ions; (d) oscillation. The cessation of the oscillation (not shown in Fig. 1) is usually abrupt, and the ceric ion concentration persists at the minimal value attained in the oscillation.

Electron-transfer reactions of the halogens and their compounds : Limiting conditions for the quantitative reaction of bromate with arsenic(iii) and antimony(iii)

The limits of hydrochloric acid concentration within which the titrimetric determination of antimony(III) and arsenic(III) with bromate is quantitative within the normal precision of careful volume measurement (0.04%), are defined for both visual indication with rosaniline hydrochloride and potentiometric indication, in media initially containing no or 0.l M bromide. These reactions are independent of the nature of the reductant, the rate-controlling step being the fourth-order reaction producing the active oxidising species. Rate constants and energy of activation were determined. The kinetic and potentiometric investigations were used to elucidate the origins of the errors arising under conditions outside the ranges of quantitative reaction.

Analytical uses of bromine monochloride: Determination of hydroxylamine. Contributions to the bromic acid-hydrochloric acid reaction

The oxidation of hydroxylamine by bromine monochloride, by elementary chlorine in hydrochloric acid medium, and by bromate and bromic acid has been investigated. Oxidation by bromine monochloride is utilised for the analytical determination of hydroxylamine. Detailed examination of the reaction of bromate with hydrochloric acid proves that, in the presence of excess of hydrochloric acid, these compounds quickly react forming bromine monochloride and elementary chlorine. The proportions of the reaction products have been determined. On the basis of the results of these investigations, it is possible to present an interpretation of the analytical method suggested by Kurtenacker for the determination of hydroxylamine.

The Kinetics of the Reaction of Sulfite and Bromate1-2

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Kinetics of the Reaction of Sulfite and Bromate1-2Frank S. Williamson and Edward L. KingCite this: J. Am. Chem. Soc. 1957, 79, 20, 5397–5400Publication Date (Print):October 1, 1957Publication History Published online1 May 2002Published inissue 1 October 1957https://doi.org/10.1021/ja01577a016RIGHTS & PERMISSIONSArticle Views117Altmetric-Citations24LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (567 KB) Get e-Alerts Get e-Alerts