DOCSLIB.ORG

LXXVI 1.-Experiments on the So-Called Migration of Atoms and Groups

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
LXXVI 1.-Experiments on the So-Called Migration of Atoms and Groups View Article Online / Journal Homepage / Table of Contents for this issue 1078 ROBINSON : EXPERIMENTS ON THE SO-CALLED LXXVI 1.-Experiments on the So-called Migration of Atoms and Groups. Pwt I. The Nityation of p-Iodoanisole and other lodo-Phenolic Ethew. By GERTRUDEMAUD ROBINSON. THE circumstances attending the niigration of atoms and groups in chemical reactions or isomeric change1 are still but; little under- stood, and it does not at present seem to be possible to include all such transformations in a single geaeralisation. In certain cases, such as the Beckmann rearrangement and the pinacone- pinacolin change, there appears to be no loophole of escape from the theory of the wadering atom, but it is quite possible that this is due to our limited knowledge of the possible intermediate stages. Orton and Jones (T., 1909, 95, 1456) have shown that the migra- tion of chlorine from side-chain to nacleus observed when N-chloro- acetanilides are treated with hydrochloric acid is due to the forma- Published on 01 January 1916. Downloaded by Temple University 25/10/2014 19:21:07. tion of an acetanilidel and chlorine, which interact with the forma- tion of the end-product substituted in the nucleus together with regenerated hydrochloric acid. The clear proof, based on a study of the dynamics of the reactions involved, is convincing, and it is natural to group analogous reactions as also due to' the interven- tion of intermediate stages, but it is not easy to realise the condi- tions in every case under which these phases may be studied. The present investigation has been undertaken in the hope that it4will prove possible to apply the theory of successive reactions, the rational explanation of migration, to a number of transformations which at present do not appear to be capable of such elucidation. A large number of examples of migration of halogen atoms from one position +,o another in the aromatic nucleus have been noted, mid the majority of these occur during the nitration or lialogena- tion of phenols, and usually these changes may be readily explained View Article Online MIGRATION OF ATOMS AND GROUPS. PART I. 1079 by the displacement of the halogen by the entering group and the re-entry by substitution in the new position. A curious reaction of this type was discovered by Reverdin (Ber., 1896, 29, 1003), who found that on nitrating piodoanisole the nitro-group displaces the iodine atom, which is apparently moved round to the ortho- position with respect to the methoxyl group. The difficulty pre- sented by this example is that the further substitution of the pnitroanisole, which may be assumed to be the initial product of ths reaction, by the iodine also obtained, is, on the surface, improb- able because pnitroanisole is not very readily converted into deriv- atives by further substitution and, further, iodine is well known to be a somewhat inactive agent. However, experiment showed that iodine does react with p-nitroanisole in nitric acid solution with the formation of the iodo-pnitroanisole obtained in the Reverdin transformation. It was also found that o-nitroanisole is changed by iodine in nitric acid solution to p-iodo-o-nitroanisole. As regards the first phase of the reaction the behaviour of iodo-pheaolic ethers with nitric acid has been examined, and itl is found that the normal reaction is the1 displacement of an iodine atom in the ortho- or para-position with respect to methoxyl with the formation of free iodine and a nitro-derivative. Thus 4 : 5-di-iodoveratrole (I) is changed successively to nitroiodoveratrole (11) and 4 : 5-dinitro- veratrole (111), and 2 : 5-di-iodoquinol dimethyl ether exhibits a similar behaviour. 3-Iodo-6-nithro-ptolylmethyl ether (IV) yields 3 : 6-dinitro-ptolyl methyl ether (V), butl in this case a by-product was found in 2 : 3 : 6-trinitro-5-hydroxy-ptolyl methyl e'ther (VI) : MeO/'\I MeO(\I MeO/\NO, Me01 Met ,,!FJ02 M~o!,/No, Published on 01 January 1916. Downloaded by Temple University 25/10/2014 19:21:07. \/11 (1.1 (11.) (111.) NO2 Me/\I MeOf\NO, Me{\OH NO,!,,!OM~ NO,\joMe NO,,,OMe NO2 (IV.1 (V.) tvr.1 In other cases which have been examined the displacement of iodine is accompanied by further nitration or oxidation. It was not found possible to isolate p-nitroanisole from the interaction of p-iodoanisole and nitric acid, since conditions where the displace- ment was possible also favoured iodination or further nitration. In considering the actual details of the mechanism of the reaction it is necessary, in the first place, to remember that the iodine is View Article Online 1080 RORTNSON : EXPERIMENTS ON THE SO-CATALED probab,Iy relmoveld from the nucleus in the form of hypoiodous acid, as shown in the scheme: OH OMe OM9 \/ OMe This then decomposes with the formation of iodine and iodic acid, and the latter sub8tance was proved to be one of the products obtained when 4 :5-di-iodoveratrole was treated with cold nitric acid (D 1.42). It is possible, but not, in the author’s opinion, very probable, that hypoiodous acid is the iodinating agent in the transformation, but it should be noted that iodine is observed to separate as such during the reaction, and this, acting on the1 nitroanisole, will produce a certain amount of hydrogen iodide which, in its turn, would be oxidised by any hypoiodous acid present. The following stages seen?, therefore, to represent the more reasonable view of the process: OMe OMe /\ /‘\ 1 +HNO, + i 1 +HOI HOT+HI -+ I,+H20 \/ \/ I NO, OMe OMe Published on 01 January 1916. Downloaded by Temple University 25/10/2014 19:21:07. (Scheme A.) Although this process must occur to some extent, it is the author’s opinion that the major proportion of the iodonitroanisole results from a process of iodination of the piodoanisole to di-iodoanisole, followed by displacement of the para-iodine atom and formation of o-iodo-pnitroanisole. Di-iodoanisole can actually be isolated as an intermediate product of the reaction, and by further treatment with nitric acid is changed to the iodonitroanisole melting at 96’. These processes are represented in scheme B: OMe OMe ON e /’\ produced in initial /‘I HNOR , -++I’ stage of A) -+ \/ ( ’ \/’ \/ I I K 0, Scheme B.) View Article Online MIGRATION OF ATOMS AND GROUPS. PART I. 1081 The remarks made in connexion with A relative to the displace- riieiit of iiitroxyl and the substitution by means of iodine or hypo- iodous acid apply also to tlie similar reactions in B. The substituting action of iodine is not observed unless the nitric acid is of a sufficient concentration, and this consideration explains the limited scope of the transformation, since a rather peculiar state of affairs must be reached. The substance dissolved in the nitric acid must have a strongly positive group, since otherwise the iodine will not be displaced; and the product must not be nitrated further at tlie concentration of acid employed, but must be capable of iodination. Even with a subst(ance so closely allied to p-iodoanisole as the corresponding o-cresol derivative the further nitration to a dinitro-compound occurs with inconvenient rapidity? and in order to observe the rearrangement it was found necessary to operate with great care. The reactions involved in this example are represented as follows : (4 OMe \/' NO2 Published on 01 January 1916. Downloaded by Temple University 25/10/2014 19:21:07. Other cases of migration of halogen atoms in phenols and their ethers will readily conform to the scheme of successive reactions and have in most cases been so represented, but Robertson and Briscoe (T., 1912, 107, 1965), who have investigated transforma- tions of this type especially arnong thymol derivatives, hold the contrary view. In certain eaamples of nitration of halogenated phenols, chlorine and bromine are displaced by nitsosyl, but remain in the molecule in a different position, whereas iodine is removed in the elementary condition, and it is supposed that the iodine is too heavy to reach the' goal when it is displaced from its position. It seems equally reasonable to assume that the iodine, once sepa- rated, does not re-enter the molecule because its reactivity is insufficient to effect the1 necessary substitution. The views of Robertson and Briscoe are founded on those of Auwers, who has very generally assumed the fact of the inigratioii of atoms and groups, basing his speculations on a considerable x x*:'" View Article Online 1082 ROBINSON : EXPERIMENTS ON THE SO-CALLED series of experimental researches which cannot well be criticised en masse. Wanderings have been assumed to occur both to the adjacent carbon atom and to the next but one, and perhaps the theoretical difficulty presented by the assumption of a true leap may be somewhat less in the former than in the latter examples. The changes of the first class can very often be explained by an application of Thiele's theory of addition to conjugated systems, as shown below for the transformation of tribromo-+-quinol into tetrabromo-p-cresol under the influence of hydrobromic acid (Auwers and Dallwig, Ber., 1902, 35, 464) : OH Me OH Me \\/ H\/ Me H/'Br +HBr + Br/'\Br + Br."Br . BA' IIBr Rr jl~r B~ ~r \/ \/ () 0 OH OH As an example of migration to the next but one carbon atom the nitration of dibromo-pcresol may be quoted, and this is the actual case which Robertson and Briscoe (Zoc. cit.) mention in support of their hypothmis. The experimental evidence adduced by Auwers (Ber., 1902, 35, 357) in support, of his contention that the reaction should be represented as shown below seems far from conclusive.
Load more

Recommended publications
  • Rate Constants for Reactions Between Iodine- and Chlorine-Containing Species: a Detailed Mechanism of the Chlorine Dioxide/Chlorite-Iodide Reaction†
    3708 J. Am. Chem. Soc. 1996, 118, 3708-3719 Rate Constants for Reactions between Iodine- and Chlorine-Containing Species: A Detailed Mechanism of the Chlorine Dioxide/Chlorite-Iodide Reaction† Istva´n Lengyel,‡ Jing Li, Kenneth Kustin,* and Irving R. Epstein Contribution from the Department of Chemistry and Center for Complex Systems, Brandeis UniVersity, Waltham, Massachusetts 02254-9110 ReceiVed NoVember 27, 1995X Abstract: The chlorite-iodide reaction is unusual because it is substrate-inhibited and autocatalytic. Because - analytically pure ClO2 ion is not easily prepared, it was generated in situ from the rapid reaction between ClO2 and I-. The resulting overall reaction is multiphasic, consisting of four separable parts. Sequentially, beginning with mixing, these parts are the (a) chlorine dioxide-iodide, (b) chlorine(III)-iodide, (c) chlorine(III)-iodine, and (d) hypoiodous and iodous acid disproportionation reactions. The overall reaction has been studied experimentally and by computer simulation by breaking it down into a set of kinetically active subsystems and three rapidly established - equilibria: protonations of chlorite and HOI and formation of I3 . The subsystems whose kinetics and stoichiometries were experimentally measured, remeasured, or which were previously experimentally measured include oxidation of - iodine(-1,0,+1,+3) by chlorine(0,+1,+3), oxidation of I by HIO2, and disproportionation of HOI and HIO2. The final mechanism and rate constants of the overall reaction and of its subsystems were determined by sensitivity analysis and parameter fitting of differential equation systems. Rate constants determined for simpler reactions were fixed in the more complex systems. A 13-step model with the three above-mentioned rapid equilibria fits the - -3 - -3 - - overall reaction and all of its subsystems over the range [I ]0 < 10 M, [ClO2 ]0 < 10 M, [I ]0/[ClO2 ]0 ) 3-5, pH ) 1-3.5, and 25 °C.
    [Show full text]
  • Measurement Report: Indirect Evidence for the Controlling Influence of Acidity on the Speciation of Iodine in Atlantic Aerosols
    Atmos. Chem. Phys., 21, 13067–13076, 2021 https://doi.org/10.5194/acp-21-13067-2021 © Author(s) 2021. This work is distributed under the Creative Commons Attribution 4.0 License. Measurement report: Indirect evidence for the controlling influence of acidity on the speciation of iodine in Atlantic aerosols Alex R. Baker1 and Chan Yodle1,a 1Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK anow at: Department of Environmental Science, Faculty of Science and Technology, Chiang Mai Rajabhat University, Chiang Mai, 50300, Thailand Correspondence: Alex R. Baker ([email protected]) Received: 26 January 2021 – Discussion started: 26 April 2021 Revised: 22 July 2021 – Accepted: 10 August 2021 – Published: 2 September 2021 Abstract. The speciation of soluble iodine and major- 1 Introduction ion composition were determined in size-fractionated aerosols collected during the AMT21 cruise between Avon- mouth, UK, and Punta Arenas, Chile, in September– Iodine (I) plays a significant role in the destruction of ozone November 2011. The proportions of iodine species (iodide, (O3) in the atmosphere (Davis et al., 1996; Saiz-Lopez et iodate and soluble organic iodine (SOI)) varied markedly be- al., 2012), being responsible for ∼ 30 % of O3 loss in the tween size fractions and with the extent to which the samples marine boundary layer (MBL) (Prados-Roman et al., 2015). were influenced by pollutants. In general, fine mode aerosols Oceanic emission, principally of volatile I2 and hypoiodous (< 1 µm) contained higher proportions of both iodide and acid (HOI) formed through the reaction of O3 with iodide − SOI, while iodate was the dominant component of coarse (I ) at the sea surface (Carpenter et al., 2013), is the main (< 1 µm) aerosols.
    [Show full text]
  • United States Patent Office Patiented Sept
    2,904,470 United States Patent Office Patiented Sept. 15, 1959 1 2 tion with bacteria or other organic matter, thus pro longing the activity of the solution. It is known that when elemental iodine is dissolved in 2,904,470 water a minute quantity of hypoiodous acid is formed. DIATOMICIODINE-HYPOIODOUS ACID GEN 5 However, this quantity of hypoiodous acid is too small to :ERATING COMPOSITIONS provide any useful therapeutic effect. It should be noted Abraham Berliner and Benjamin Carroll, New York, N.Y. that the solutions of the present invention contain hy poiodous acid at a concentration greater than that pro "No Drawing. Application December 1, 1955 duced when iodine is dissolved in water. Also the solu Serial No. 550,463 0 tions are preferably essentially free from iodide and tri iodide ions. 7 Claims, (Cl. 167-70) We have further found that aqueous solutions of diatomic iodine and hypoiodous acid are relatively un stable and that if effective germicidal action is to be This invention relates to germicides and more par 5 achieved the solutions must be prepared under carefully -ticularly to a novel iodine containing composition that controlled conditions as described herein. Because of the is adapted to be dissolved in water to produce an aqueous comparative instability of the solutions, it is desirable solution of diatomic iodine and hypoiodous acid, which that they be prepared shortly before they are used and solution is also new and possesses improved germicidal accordingly the present invention contemplates the use properties. Germicidal iodine-containing solutions made 20 of a solid composition which is readily soluble in water according to the present invention may be used for either and contains all the ingredients necessary to produce the therapeutic purposes or as sterilizing agents for a variety desired germicidal solution.
    [Show full text]
  • ATOMIC ENERGY F F S L'energie ATOMIQUE of CANADA UMITED T
    AECL-6f)2 ATOMIC ENERGY ffS L'ENERGIE ATOMIQUE OF CANADA UMITED Tif T DU CANADA UMITEE ASSESSMENT OF IODINE BEHAVIOUR IN REACTOR CONTAINMENT BUILDINGS FROM A CHEMICAL PERSPECTIVE EVALUATION DU COMPORTEMENT CHIMIQUE DE L'lODE DANS L'ENCEINTE DE PROTECTION D'UN REACTEUR Robert J. Lemire', Jean Paquette, David F. Torgerson , David J. Wren1, J. Wallace Fletcher2 Whiteshell Nuclear Research Establishment Etablissement de Recherches Nucle'aires de Whiteshell * Chalk River Nuclear Laboratories Laboratoires Nucleaires de Chalk River Whiteshell Nuclear Research Etablissement de Recherches Establishment Nucle'aires de Whiteshell Pinawa, Manitoba ROE 1L0 June T981 juin ATOMIC ENERGY OF CANADA LIMITED ASSESSMENT OF IODINE BEHAVIOUR IN REACTOR CONTAINMENT BUILDINGS FROM A CHEMICAL PERSPECTIVt by Robert J. Lemire , Jean Paquette , David F. Torgersor) , 1 2 David J. Wren and J. Wallace Fletcher Research Chemistry Branch Whiteshell Nuclear Research Establishment Physical Chemistry Branch Chalk River Nuclear Laboratories Whiteshell Nuclear Research Establishment Pinawa, Manitoba ROE 1L0 1981 June AECL-6812 EVALUATION DU COMPORTEMENT CHIMIQUE DE L'IODE DANS L'ENCEINTE DE PROTECTION D'UN REACTEUR par Robert J. Lemire , Jean Paquet te , David F. ïorgerson , 1 2 David J. Wren et J. Wallace Fletcher RESUME Les paramètres thermodynamiques pour les espèces aqueuses, solides et gazeuses de l'iode à 25°C ont été obtenus à partir d'un examen de la littérature chimique. Ces données ont été rendues com- patibles avec la compilation du groupe CODATA. En utilisant les données thermodynamiques à 25°C, les valeurs de l'énergie libre de formation ont été évaluées en fonction de la température, jusqu'à 150°C, et ce pour toutes les espèces de l'iode.
    [Show full text]
  • 6. Potential for Human Exposure
    IODINE 233 6. POTENTIAL FOR HUMAN EXPOSURE 6.1 OVERVIEW The stable isotope of iodine, 127I, and two of its radioactive isotopes, 129I and 131I, have been identified in at least 8, 3, and 6, respectively, of the 1,636 hazardous waste sites that have been proposed for inclusion on the EPA National Priorities List (NPL) (HazDat 2004). However, the number of sites evaluated for iodine is not known. The frequency of these sites can be seen in Figures 6-1, 6-2, and 6-3. All of these sites are located within the United States. Iodine is a naturally occurring constituent of the earth’s crust and is the least abundant of the halogen elements (Straub et al. 1966). The stable isotope iodine, 127I, is ubiquitous throughout the earth’s surface. The concentration of 127I in the earth’s crust is approximately 0.5 ppm; in the oceans, the concentration is 45–60 µg/L, and in the atmosphere, the concentration ranges from 10 to 20 ng/m3. Concentrations of iodine in the environment throughout the United States vary depending on the proximity to the seacoast and the soil type. The concentration of iodine in bedrock varies between 0.5 and 380 ppm, depending on whether the rock is igneous or sedimentary. Iodine exists in many chemical forms (e.g., molecular iodine, iodide, iodate, periodate) and can undergo oxidation-reduction as well as microbial alkylation (mostly methyl iodide). Iodine has nine radioisotopes, of which 123I, 125I, 129I, and 131I are commonly encountered in acute or chronic exposures to human populations, due either to the life-times of the radioisotope in the environment, their production, and/or their use in industry, medicine, and research.
    [Show full text]
  • Identification of Promising Remediation Technologies for Iodine in the UP-1 Operable Unit
    PNNL-26934 RPT-DVZ-AFRI-050 Identification of Promising Remediation Technologies for Iodine in the UP-1 Operable Unit September 2017 CE Strickland CD Johnson BD Lee NP Qafoku JE Szecsody MJ Truex VR Vermeul PNNL-26934 RPT-DVZ-AFRI-050 Identification of Promising Remediation Technologies for Iodine in the UP-1 Operable Unit CE Strickland CD Johnson BD Lee NP Qafoku JE Szecsody MJ Truex VR Vermeul September 2017 Prepared for the U.S. Department of Energy under Contract DE-AC05-76RL01830 Pacific Northwest National Laboratory Richland, Washington 99352 Executive Summary Iodine-129 (129I) generated at the U.S. Department of Energy (DOE) Hanford Site during plutonium production was released to the subsurface, resulting in several large, though dilute, plumes in the groundwater, including the plume in the 200-UP-1 operable unit (OU). Because 129I is an uncommon contaminant, relevant remediation experience and scientific literature are limited, though work is under way to better understand the fate and transport of 129I in the environment and the effectiveness of potential remediation technologies. The recent UP-1 Evaluation Plan for Iodine1 and report on the Conceptual Model of Iodine Behavior in the Subsurface at the Hanford Site2 provide information on the history of contamination in the 200-UP-1 OU, relevant controlling processes (biological and geochemical), risk, the conceptual site model, and potential remedial options, which provided a foundation for this study. In this study, available information was compiled and used to categorize potential remediation technologies, culminating in a recommendation of promising technologies for further evaluation. Approaches to improve the technical information about promising technologies are also recommended in this study so that a subsequent evaluation of potential remediation alternatives can assess these technologies.
    [Show full text]
  • Post Treatment Alternatives for Stabilizing Desalinated Water
    University of Central Florida STARS Electronic Theses and Dissertations, 2004-2019 2009 Post Treatment Alternatives For Stabilizing Desalinated Water Susaye Douglas University of Central Florida Part of the Environmental Engineering Commons Find similar works at: https://stars.library.ucf.edu/etd University of Central Florida Libraries http://library.ucf.edu This Masters Thesis (Open Access) is brought to you for free and open access by STARS. It has been accepted for inclusion in Electronic Theses and Dissertations, 2004-2019 by an authorized administrator of STARS. For more information, please contact [email protected]. STARS Citation Douglas, Susaye, "Post Treatment Alternatives For Stabilizing Desalinated Water" (2009). Electronic Theses and Dissertations, 2004-2019. 4065. https://stars.library.ucf.edu/etd/4065 POST TREATMENT ALTERNATIVES FOR STABILIZING DESALINATED WATER by SUSAYE S DOUGLAS B.S. University of Central Florida, 2007 A Thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in the Department of Civil, Environmental, and Construction Engineering in the College of Engineering and Computer Science at the University of Central Florida Orlando, Florida Summer Term 2009 ©2009 Susaye S Douglas ii ABSTRACT The use of brackish water and seawater desalination for augmenting potable water supplies has focused primarily on pre-treatment, process optimization, energy efficiency, and concentrate management. Much less has been documented regarding the impact of post-treatment requirements with respect to distribution system. The goals of this study were to review current literature on post-treatment of permeate water, use survey questionnaires to gather information on post-treatment water quality characteristics, gather operation information, review general capital and maintenance cost, and identify appropriate “lessons learned” with regards to post-treatment from water purveyors participating in the Project.
    [Show full text]
  • Nomenclature of Organic Chemistry. IUPAC Recommendations and Preferred Names 2013
    International Union of Pure and Applied Chemistry Division VIII Chemical Nomenclature and Structure Representation Division Nomenclature of Organic Chemistry. IUPAC Recommendations and Preferred Names 2013. Prepared for publication by Henri A. Favre and Warren H. Powell, Royal Society of Chemistry, ISBN 978-0-85404-182-4 Chapter P-6 APPLICATIONS TO SPECIFIC CLASSES OF COMPOUNDS (continued) (P-66 to P-69) (continued from P-60 to P-65) P-60 Introduction P-61 Substitutive nomenclature: prefix mode P-62 Amines and imines P-63 Hydroxy compounds, ethers, peroxols, peroxides and chalcogen analogues P-64 Ketones, pseudoketones and heterones, and chalcogen analogues P-65 Acids and derivatives P-66 Amides, hydrazides, nitriles, aldehydes P-67 Oxoacids used as parents for organic compounds P-68 Nomenclature of other classes of compounds P-69 Organometallic compounds P-66 AMIDES, IMIDES, HYDRAZIDES, NITRILES, AND ALDEHYDES, P-66.0 Introduction P-66.1 Amides P-66.2 Imides P-66.3 Hydrazides P-66.4 Amidines, amidrazones, hydrazidines, and amidoximes (amide oximes) P-66.5 Nitriles P-66.6 Aldehydes P-66.0 INTRODUCTION The classes dealt with in this Section have in common the fact that their retained names are derived from those of acids by changing the ‘ic acid’ ending to a class name, for example ‘amide’, ‘ohydrazide’, ‘nitrile’, or ‘aldehyde’. Their systematic names are formed substitutively by the suffix mode using one of two types of suffix, one that includes the carbon atom, for example, ‘carbonitrile’ for –CN, and one that does not, for example, ‘-nitrile’ for –(C)N. Amidines are named as amides, hydrazidines as hydrazides, and amidrazones as amides or hydrazides.
    [Show full text]
  • NATURE August 3, 1957 Vol
    250 NATURE August 3, 1957 voL. 1ao absence of any change in the slight influence of a hypoiodous acid and iodide in equal amounts. (The nearby ionizing electron discharge upon the speed hypoiodous acid and iodide take part in an equili­ of pumping of the carbon monoxide {condensation brium to give a trace of iodine which is volatile.) coefficient), suggests that the gas molecules (neutral (3) The ratio of total iodine/chloride is higher in or ionized) are not taken up directly by the barium, warm, partly enclosed sea areas•. This is to be ex­ but are first dissociated into oxygen and carbon. pected from the effect of temperature upon the Thus the reaction is one of oxidation in the presence equilibria mentioned in (1) and (2) 2, which results of carbon, and so the qualitative similarity between in a. marked increase in the content of volatile iodine the behaviour of barium towards oxygen and carbon molecules when sea water is cooled. monoxide is to be expected. Whereas the hypothesis accounts for these findings, In some details, there are important differences it should be noted that iodate and not hypoiodous between the reactions in the two cases. In the case acid would be the thermodynamically stable form of of oxygen, it was found• that the first monolayer of oxidized iodine in the sea. However, it seems likely o1'-ygen was only taken up if there were nucleation that the rate of iodate formation from hypoiodous centres in the surface of the barium film. Ordinarily, acid, a third-order reaction in near-neutral solution', such centres always exist in the surface of getter will be slow at the very low hypoiodous acid con­ films deposited in a fraction of a minute and at centrations in sea water.
    [Show full text]
  • Chemistry 192 Problem Set 5 Spring, 2018 Solutions
    Chemistry 192 Problem Set 5 Spring, 2018 Solutions 1. In a titration experiment varying amounts of a 0.0100 M sodium hydroxide solution are added to 100. mL of 0.053 M hydrochloric acid. Determine the following: (a) the volume of the sodium hydroxide solution required to produce a solution of pH=7.0; Answer: + −1 moles of H3O = (0:053 mol L )(0:100 L) = 0:0053 mol 0:0053 mol V = = 0:53 L ≡ 530: mL 0:0100 mol L−1 (b) the pH of the solution if the amount of sodium hydroxide solution added is 10.0 mL less than the volume found in problem 1a; Answer: + −1 number of moles of H3O remaining = 0:0053 mol − (0:52 L)(0:0100 mol L ) = 0:00010 mol 0:00010 mol [H O+] = = 1:6 × 10−4 M 3 0:620 L −4 pH = − log10(1:6 × 10 ) = 3:79 (c) the pH of the solution if the amount of sodium hydroxide solution added is 10.0 mL more than the volume found in problem 1a. Answer: (0:010 L)(0:0100 mol L−1) [OH−] = = 1:6 × 10−4 M 0:640 L −4 pOH = − log10(1:6 × 10 ) = 3:81 pH = 14:00 − pOH = 10:19 1 2. In a titration experiment varying amounts of a 0.0100 M sodium hydroxide solution are added to 100. mL of 0.046 M benzoic acid (the pKa of benzoic acid is found on page 745 of your textbooks). Determine the following: (a) the volume of the sodium hydroxide solution required to reach the equivalence point; Answer: number moles benzoic acid = (0:046 mol L−1)(0:100 L) = 0:0046 mol = moles OH−needed 0:0046 mol V = = 0:46 L 0:0100 mol L−1 (b) the pH of the solution at the equivalence point; Answer: At the equivalence point, all benzoate is in the form of sodium benzoate.
    [Show full text]
  • Iodine As a Drinking Water Disinfectant
    Iodine as a drinking water disinfectant Draft Document 5.4 24 October 2016 Version for Public Review Contents Contents ............................................................................................................................................... i List of abbreviations ............................................................................................................................ 1 1 Introduction ......................................................................................................................................... 2 2 Disinfectant mode of action and efficacy ............................................................................................ 3 2.1 Chemistry basics ........................................................................................................................... 3 2.1.1 Water solubility, taste, odour and colour .............................................................................. 3 2.1.2 Chemical speciation of iodine in water and corresponding disinfection powers .................. 4 2.1.2.1 Effect of pH ..................................................................................................................... 5 2.1.2.2 Effect of temperature ..................................................................................................... 7 2.2 Efficacy of iodine ........................................................................................................................... 7 2.2.1 Bactericidal efficacy of iodine ...............................................................................................
    [Show full text]
  • Measurement of Iodine Species and Sulfuric Acid Using Bromide
    https://doi.org/10.5194/amt-2020-494 Preprint. Discussion started: 18 December 2020 c Author(s) 2020. CC BY 4.0 License. 1 Measurement of iodine species and sulfuric acid using bromide 2 chemical ionization mass spectrometers 3 4 Mingyi Wang1,2*, Xu-Cheng He3*#, Henning Finkenzeller4, Siddharth Iyer3, Dexian Chen1,5, Jiali 5 Shen3, Mario Simon6, Victoria Hofbauer1,2, Jasper Kirkby6,7, Joachim Curtius6, Norbert Maier8, 6 Theo Kurtén3,8, Douglas R. Worsnop3,9, Markku Kulmala3,10,11,12, Matti Rissanen3,13, Rainer 7 Volkamer4, Yee Jun Tham3#, Neil M. Donahue1,2,5,14, and Mikko Sipilä3 8 9 1Center for Atmospheric Particle Studies, Carnegie Mellon University, Pittsburgh, PA, 15213, USA 10 2Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA, 15213, USA 11 3Institute for Atmospheric and Earth System Research (INAR), University of Helsinki, 00014 Helsinki, Finland 12 4Department of Chemistry & CIRES, University of Colorado Boulder, Boulder, CO 80309, USA 13 5Department of Chemical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA 14 6Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt, 60438 Frankfurt am Main, 15 Germany 16 7CERN, the European Organization for Nuclear Research, CH-1211 Geneve 23, Switzerland 17 8Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland 18 9Aerodyne Research, Inc., Billerica, MA, 01821, USA 19 10Helsinki Institute of Physics, P.O. BoX 64 (Gustaf Hallstromin katu 2), FI-00014 University of Helsinki, Finland 20 11Joint International Research
    [Show full text]