Equilibrium Quotients Research Articles

Theoretical Studies of Slag Exchange Equilibria

Abstract Equations for the concentration dependence of slag exchange equilibria are deduced from the coordination cluster theory. The most important influence on this concentration dependence is preferential solvation of solute components by a solvent component. The linear concentration dependence of the logarithm of equilibrium quotients deduced by Flood and Grjotheim is valid for cases where there is essentially no preferential solvation and almost random mixing of solvent ions. Deviations from the Flood-Grjotheim equation should be generally large for non-ideal slags in which one solvent component interacts more strongly with solutes than do the other solvent components. The equations derived in this work provide insights into the physical factors which influence the magnitude and concentration dependence of exchange equilibria. Resume A partir de la theorie du “cluster de coordination” les variations des equilibres d'echange dans le laitier avec la composition ont ete etudiees. L'influence preponderan...

The solubility of thorium fluoride in nitric acid-hydrofluoric acid solution between 25 and 100°C

Abstract The solubility of thorium fluoride in 4, 8, and 13 M nitric acid solutions was measured as a function of fluoride concentration at 25, 50 and 100°C. The behavior of the solubility is best explained by the existence in solution of the species ThF n (4− n )+ , where n has values between 0 and 4. Equilibrium quotients for the stepwise complexation of thorium by fluoride are calculated.

Intramolecular association of 1,N6-ethenoadenylyl-(3'.fwdarw.5')-1,N6-ethenoadenosine (.epsilon.Ap.epsilon.A). A comparison of intramolecular stacking equilibrium quotients estimated by different methods

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntramolecular association of 1,N6-ethenoadenylyl-(3'.fwdarw.5')-1,N6-ethenoadenosine (.epsilon.Ap.epsilon.A). A comparison of intramolecular stacking equilibrium quotients estimated by different methodsYasuo Inoue, Takao Kuramochi, Michiharu Sakurai, and Ichiro TazawaCite this: J. Am. Chem. Soc. 1980, 102, 17, 5574–5577Publication Date (Print):August 1, 1980Publication History Published online1 May 2002Published inissue 1 August 1980https://doi.org/10.1021/ja00537a026RIGHTS & PERMISSIONSArticle Views27Altmetric-Citations7LEARN 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 (486 KB) Get e-Alerts Get e-Alerts

Solvent Extraction Chemistry and Kinetics of Zirconium

Abstract The solvent extraction behavior of zirconium in the HN03-tributyl phosphate (TBP) system can be explained based on the existence of four principal aqueous species, Zr4+, ZrOH3+, Zr3(OH)8+ 4, and oxo-polymers. The Zr4+ and ZrOH3+ species are extractable and are in equilibrium with inextractable Zr3(OH)8+ 4. The oxo-polymers are formed by heat, are-inextractable, and are not: in equilibrium with the other species. The aqueous equilibria and their equilibrium quotients have been previously determined. In the present study, these equilibria were used along with both tracer and macro zirconium concentrations (oxo-polymers excluded by extraction and back scrubbing) to determine the distribution equilibrium constants for both the Zr4+ and ZrOH3+ ions. The four equilibrium constants give excellent fits to both tracer and macro-zirconium distribution data. The concentrations of the extractable zirconium species which are calculated from the equilibria have been used to begin examining the extraction kinet...

Fluorosilicate equilibriums in sodium chloride solutions from 0 to 60.degree.C

A potentiometric method employing quinhydrone and solid-state fluoride electrodes was used to observe the free hydrogen ion and the free fluoride ion concentrations in equilibrium experiments in aqueous solutions at 0 to 60/sup 0/C. In dilute silicic acid solutions the predominant reaction can be expressed as Si(OH)/sub 4/(aq) + 4H/sup +/ + 6F/sup -/ reversible SiF/sub 6//sup 2 -/ + 4H/sub 2/O. The logarithm of the equilibrium quotient has values of 31.610, 29.980, and 28.23 at 0, 25, and 60/sup 0/C in 1 m NaCl (molal units). There is evidence for the existence of small amounts of additional species with fewer fluorides under certain conditions. The absence of a regular sequence of species from the array Si(OH)/sub 4-x/ F/sub y//sup x-y/ is proven by an analysis of the results. The average number of fluoride ions complexed by millimolal silicic acid approaches 6.0 in 0.01 m fluoride as the pH is reduced to 3 or lower in titration experiments. Simultaneously the average number of hydrogen ions consumed approaches 4.0. 2 tables, 4 figures.

Kinetics and Mechanism of Oxidation of Promazine and Promethazine by Ferric Perchlorate

The equilibrium constants, kinetics, and mechanism of promazine and promethazine oxidation by ferric perchlorate were investigated at different temperatures and acidities using a stopped-flow spectrophotometric technique. The overall reaction can be represented as follows: (formula: see text) where P+ represents the radical cation corresponding to the phenothiazine derivative. The equilibrium quotients were evaluated at 1.00 M HClO4, 25.0 degrees, and ionic strength 1.0 M. The kinetics of reaction follow the equation: -d[P] divided by dt = k1[Fe3+][P]-k-1[Fe2+][P+] The rate constants k1 and k-1 are independent of acidity and are related to the corresponding equilibrium quotients.

ChemInform Abstract: KINETIC AND EQUILIBRIUM PARAMETERS FOR THE REACTION OF NEPTUNIUM(III) WITH TRIS(ETHYLENEDIAMINE)RUTHENIUM(III)

The kinetic and equilibrium parameters for the reaction Np/sup 3 +/ + Ru(en)/sub 3//sup 3 +/ broken arrows Np/sup 4 +/ + Ru(en)/sub 3//sup 2 +/ have been determined in aqueous trifluoromethanesulfonate media. The observed forward rate constants (in M/sup -1/ s/sup -1/, ..mu.. = 1.00 M) are: 6.40 +- 0.23 (4.3/sup 0/C), 8.96 +- 0.38 (25/sup 0/C), and 9.78 +- 0.60 (40.3/sup 0/C). The enthalpy and entropy of the reaction are -12.6 +- 1.0 kcal/mol and -41.5 +- 3.3 eu. respectively. From these values, the E/sub f/ for Ru(en)/sub 3//sup 3+/2+/ in 1.0 M HCF/sub 3/SO/sub 3/ at 25/sup 0/C is calculated to be 0.167 V, in close agreement with the value of 0.172 V (..mu.. = 0.013 M) previously determined electrochemically. Activation parameters and the temperature dependence of the equilibrium quotients are similar to those determined for reactions of Np/sup 3 +/ with Ru(NH/sub 3/)/sub 6//sup 3 +/ and Ru(NH/sub 3/)/sub 5/H/sub 2/O/sup 3 +/. From the Marcus cross relation, the self-exchange rate for Ru(en)/sub 3//sup 2+/3+/ is calculated to be 5 times the corresponding rate for Ru(NH/sub 3/)/sub 6//sup 2+/3+/ in contrast to the value of 0.25 times this rate reported earlier. The relative exchange rate formore » these two species, as calculated from expected outer-sphere reorganization energy differences, is of the same order of magnitude and direction as we report.« less

On the properties of solid and liquid ion exchangers—V: The potassium-hydrogen exchange on dinonylnaphthalene sulfonic acid in heptane in the temperature range 1–80°C

Abstract The potassium-hydrogen exchange on dinonylnaphthalene sulfonic acid dissolved in heptane has been studied in the temperature range 1–80°C using batch techniques and titrimetric analysis. The data can be fitted with a simple model, where it is assumed that the system contains three kinds of micelles, HDNNS-micelles. KDNNS-micelles and a mixed micelle (K. H)DNNS each with a different ion exchange constant. The relation between the experimental value for the equilibrium quotient (κ) and the three parameters κ 1 , κ 2 and κ 3 is log κ= X log κ 1 +{l− X } log κ 2 + X (l− X ) log κ 3 where X is the mole fraction of potassium in the organic phase, i.e. the distribution of micelles is assumed to be statistical. From the curves log κ( 1 T ) x the function ΔH( X ) is obtained at each temperature. These data can be fitted with the same model i.e. δH ° =δH 1 ° X +δH 2 ° (1− X )+δH 3 ° X (1− X ) Together with the free energy data ( ΔG ° = − RT ln κ ) entropies are computed for the three kinds of micelles. It is found that while the two pure micelles have negative entropy changes, the mixed micelle has a positive entropy change, provided the assumptions inherent for the equation above are correct. The mixed micelle concept also explains the water extraction in the system HDNNS-KDNNS in heptane as shown for data at 25°C.

Ionization equilibriums of silicic acid and polysilicate formation in aqueous sodium chloride solutions to 300.degree.C

The ionization behavior of silicic acid and polysilicate formation in basic solutions have been studied by precise potentiometry using titration techniques in a hydrogen-electrode concentration cell. Polysilicate formation was studied in 1 m NaCl solutions at temperatures from 60 to 290/sup 0/C and at Si(IV) concentrations 0.005 to 0.05 m. At the lowest silica concentration only mononuclear species occur over wide temperature and pH ranges. At hydroxyl numbers from about 0.7 to 1.0 (average charge per silicon) small polysilicates which equilibrate rapidly occur at higher Si(IV) concentrations. Polysilicate formation decreases with increasing temperature. The equilibrium quotient for the most significant reaction, Si(OH)/sub 4/(aq) + OH/sup -/ broken arrows SiO(OH)/sub 3//sup -/ + H/sub 2/O, has been precisely determined from 0.1 to 5.0 m NaCl and to about 300/sup 0/C. Values of the logarithm of the equilibrium quotient for the reaction are 3.96 and 2.20 at 50 and 300/sup 0/C in 1 m NaCl and 4.32 and 2.26 at the same two temperatures in 5 m NaCl. An analytical expression from which the thermodynamic quantities for the reaction can be computed is presented. The small effect of salt concentration is interpreted as evidence for little or no sodium ion complexing.

ChemInform Abstract: TITRATION PROPERTIES OF HOMODINUCLEOSIDE MONOPHOSPHATES. DETERMINATION OF OVERLAPPING IONIZATION CONSTANTS AND INTRAMOLECULAR STACKING EQUILIBRIUM QUOTIENTS OF APA, CPC, GPG, AND UPU

Chemischer InformationsdienstVolume 8, Issue 5 Natural Products ChemInform Abstract: TITRATION PROPERTIES OF HOMODINUCLEOSIDE MONOPHOSPHATES. DETERMINATION OF OVERLAPPING IONIZATION CONSTANTS AND INTRAMOLECULAR STACKING EQUILIBRIUM QUOTIENTS OF APA, CPC, GPG, AND UPU N. OGASAWARA, N. OGASAWARASearch for more papers by this authorY. INOUE, Y. INOUESearch for more papers by this author N. OGASAWARA, N. OGASAWARASearch for more papers by this authorY. INOUE, Y. INOUESearch for more papers by this author First published: February 1, 1977 https://doi.org/10.1002/chin.197705353AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume8, Issue5February 1, 1977 RelatedInformation

Association between Fe(OH 2) 62+ and trans-[Os(en) 2O 2] 2+

Abstract Aqueous solutions of Fe(OH 2 ) 6 2+ interact producing an intensely blue colored ion of the formula [(OH 2 ) 5 FeOOs(en) 2 O] 4+ which has been isolated in the solid state as the sulfate salt. Oxidation-reduction is not involved and the formation and dissociation are rapid. Equilibrium quotients have been evaluated and it is shown that K 2 ⪢ K 1 .

Photochemical reactions of aqueous plutonium systems—II

The photochemical shift of the Pu4+ disproportionation equilibrium in aqueous perchloric acid solutions has been measured and shown to be reversible. Ratios of equilibrium quotients between light and dark conditions have been measured for 0.01 M Pu ion concentrations in 0.53 to 1.24 N acid solutions exposed to 0.5 Watt of UV light. The photodecomposition of time- and temperature-aged Pu(IV) polymers in perchloric and nitric acid solutions have been examined as a function of aging conditions. Effects similar to those seen previously for fresh polymers have been observed in the aged perchloric acid solutions.

Titration and temperature-dependent properties of homodinucleoside monophosphates. Evaluation of stacking equilibrium quotients for neutral and half-ionized ApA, CpC, GpG, and UpU.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTitration and temperature-dependent properties of homodinucleoside monophosphates. Evaluation of stacking equilibrium quotients for neutral and half-ionized ApA, CpC, GpG, and UpUNaotake Ogasawara and Yasuo InoueCite this: J. Am. Chem. Soc. 1976, 98, 22, 7054–7060Publication Date (Print):October 1, 1976Publication History Published online1 May 2002Published inissue 1 October 1976https://doi.org/10.1021/ja00438a053RIGHTS & PERMISSIONSArticle Views42Altmetric-Citations18LEARN 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 (801 KB) Get e-Alerts Get e-Alerts

Titration properties of homodinucleoside monophosphates. Determination of overlapping ionization constants and intramolecular stacking equilibrium quotients of ApA, CpC, GpG, and UpU.

Titration properties of homodinucleoside monophosphates. Determination of overlapping ionization constants and intramolecular stacking equilibrium quotients of ApA, CpC, GpG, and UpU.

Temperature-jump study of the reaction between hexacyanoferrate(II) and -(III) and tris(phenanthroline)cobalt(II) and -(III)

Outer-sphere redox reactions of metal ions and complexes, normally studied with ions of the same charge, were studied here using reactants of opposite charge in an effort to determine the component parts of the second order rate coefficient. The Co(phen)/sub 3//sup 3 +/-Fe(CN)/sub 6//sup 4 -/ system was studied spectrophotometrically to determine the equilibrium quotient; and entropy and enthalpy calculations were made using the equilibrium data. A temperature-jump apparatus was used for kinetic measurements. The rate coefficient components could not be determined for this system, however, the results indicate the importance of electrostatic factors in outer-sphere reaction rate considerations. (DDA)

Bi- and ter-molecular electron donor–acceptor complex formation between hexamethylbenzene and 1,3,5-trinitrobenzene, and also between NNN′N′-tetramethyl-p-phenylenediamine and 1,3,5-trinitrobenzene in solution

The dependence of the line position in the 1H n.m.r. spectra of dilute solutions of the electron acceptor (A) 1, 3, 5-trinitrobenzene on the concentration of excess of the electron donor (D) hexamethylbenzene in various paraffinic solvents has been interpreted in terms of equilibria involving the complex species DA and D2A. The equilibrium quotients have been evaluated on several concentration scales.The same interpretation provides a satisfactory explanation for similar observations involving the interaction of NNN′N′-tetramethyl-p-phenylenediamine with 1, 3, 5-trinitrobenzene. The results are in accord with those obtained from optical measurements.Activity coefficient effects in themselves appear to be too small to provide an alternative explanation of the observed behaviour.

Cis-dichlorodiammineplatinum(II). Aquation equilibria and isotopic exchange of chloride ligands with free chloride and tetrachloroplatinate(II)

Abstract The equilibrium quotients for the first and second aquation steps of c-Pt(NH 3 ) 2 Cl 2 have been determined by a titration technique. At 25.0° C and an ionic strength of 0.318M the first and second aquation equilibrium constants are: K 1 = 3.63 ± .22 × 10 −3 M, ΔH° 1 = 3.4 kcal and K 2 = 1.11 ± .14 × 10 −4 M, AH° 2 = 10 kcal. The kinetics of isotopic exchange of chlorine was investigated in the ternary system: c-Pt(NH 3 ) 2 Cl 2 , PtCl 4 2− , Cl − . In addition to exchange via the route of aquation, a direct exchange of chloride between c-Pt (NH 3 ) 2 Cl 2 and PtCl 4 2− occurred which is described by the rate expression: R = [c-Pt(NH 3 ) 2 Cl 2 ][PtCl 4 2− ](k ac ′ + k ac ″[Cl − −1 ). At 25° C the rate constants were k ac ′ = 3.0 × 10-4 M −1 sec −1 and k ac ″ = 9.0 × 10-5 sec 1.

ChemInform Abstract: FOURIER TRANSFORM CARBON‐13 NUCLEAR MAGNETIC RESONANCE OF AQUEOUS NICKEL(II)‐ACETIC ACID SOLUTIONS, PART 1, EQUILIBRIUM QUOTIENTS FROM RELATIVE ABUNDANCES OF SOLUTION SPECIES

Chemischer InformationsdienstVolume 6, Issue 42 Organoelement Compounds ChemInform Abstract: FOURIER TRANSFORM CARBON-13 NUCLEAR MAGNETIC RESONANCE OF AQUEOUS NICKEL(II)-ACETIC ACID SOLUTIONS, PART 1, EQUILIBRIUM QUOTIENTS FROM RELATIVE ABUNDANCES OF SOLUTION SPECIES R. JUN. FUENTES, R. JUN. FUENTESSearch for more papers by this authorL. O. MORGAN, L. O. MORGANSearch for more papers by this authorN. A. MATWIYOFF, N. A. MATWIYOFFSearch for more papers by this author R. JUN. FUENTES, R. JUN. FUENTESSearch for more papers by this authorL. O. MORGAN, L. O. MORGANSearch for more papers by this authorN. A. MATWIYOFF, N. A. MATWIYOFFSearch for more papers by this author First published: October 21, 1975 https://doi.org/10.1002/chin.197542409AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume6, Issue42October 21, 1975 RelatedInformation

Fourier transform carbon-13 nuclear magnetic resonance of aqueous nickel(II)-acetic acid solutions. I. Equilibrium quotients from relative abundances of solution species

The complex formation reaction between nickel(II) and acetate ions in aqueous solution has been studied by Fourier transform carbon-13 nuclear magnetic resonance. Equilibrium quotients for the formation of monoacetatonickel(II) complex were calculated from the relative areas of distinct coordinated and bulk acetate signals over the temperature range -5 to +20/sup 0/ and were found to be constant over this range. Equilibrium quotients determined over the ionic strength range 1.2--4.0 m were found to be smaller than previously reported values. A minimum in the equilibrium quotient was observed at approximately 2 m ionic strength.

ChemInform Abstract: AQUATION OF CHLOROPENTAAMMINECOBALT(III) PERCHLORATE IN CHLORIDE‐ION CONTAINING WATER‐NONAQUEOUS SOLVENT MIXTURES

The equilibrium quotients for the formation of Co(NH3)5Cl2+ from Co(NH3)5OH23+ and Cl− were 3.74±0.25 M−1 and 6.07±0.54 M−1 at 45.0°C in 10:1 mole ratio water: dimethyl sulfoxide and in 25 w/w % aqueous ethanol, respectively, and those forthe formation of the ion pair Co(NH3)5OH23+ . Cl− were 1.21±0.20 M−1 and 1.58±0.17 M−1, respectively, in the same solvents. The aquation and anation rateconstants were determined at 45.0°C for these two solvents over the range of chloride-ion concentrations 0.0 ≤ [Cl−] ≤ 0.9 M. The aquation rate constant was essentially independent of chloride-ion concentration in each solvent over this range. The inverse of the pseudo-first-order anation rate constant was linearly dependent on the inverse of the chloride-ion concentration in each solvent. The least squares relationships between (1/kan) and (1/[Cl−]) gave intercepts and ratios of intercept to slope which were analyzed interms of Id and D mechanisms. It was concluded that the data were not satisfied by a D mechanism, but that they were consistent with an Id mechanism.