Mutual diffusion coefficients of Nal-H2O and LiCl-H2O at 25°C from Rayleigh interferometry

Volume-fixed mutual diffusion coefficients of aqueous NaI have been measured from low concentrations to 10.8 mol-(kg H₂O)^–1 (7.6 mol-dm^–3), and those of LiCl up to 1.6 mol-(kg H₂O)^–1 (1.55 mol-dm^–3), at 25°C using free-diffusion Rayleigh interferometry. The accuracy of these diffusion coefficients is 0.1–0.2%. LiCl-H₂O has some of the lowest diffusion coefficients for alkali halides, whereas NaI-H₂O has some of the highest. The significance of these differences is briefly discussed.Work performed under the auspices of Office of Basic Energy Science (Geosciences) of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under contract number W-7405-ENG-48.     

Thermodynamic properties of aqueous-organic systems with low water contents. 2. Limiting partial molar volumes of D2O and H2O intert-butyl alcohol and 1,4-dioxane at 288.15–318.15 K

The densities of dilute solutions of H₂O and D₂O in 1,4-dioxane and tert-BuOD have been measured in the interval 288.15–318.15 K with an error of 2·10^–6 g/cm³. The limiting partial molar volumes of D₂O and H₂O in 1,4-dioxane andtert-butanol have been determined by using an original procedure; the changes in the partial molar volume of water due to H-D substitution in the water molecules have been calculated. The analysis of the temperature dependence of the partial volumes of the components of the binary mixtures H₂O (D₂O) + 1,4-dioxane and H₂O (D₂O) +tert-BuOH (tert-BuOD) showed on the basis of Maxwell's crossing equations that the addition of small amounts of water significantly alters the structure of the unary organic solvent. In the presence of trace amounts of water the expansibility of 1,4-dioxane increases and that oftert-butanol decreases.For previous communication, see [1].Institute of the Chemistry of Nonaqueous Solutions, Russian Academy of Sciences, Ivanovo 153018. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 568–571, March, 1992.     

Infrared spectra (700–200 cm−1) and6Li/7Li and H2O/D2O isotope effects for four isotopically substituted lithium formate monohydrates

The infrared spectra, in the 700–200 cm^–1 region, have been reported for⁶LiHCO₂ · H₂O,⁶LiHCO₂ · D₂O,⁷LiHCO₂ · H₂O and⁷LiHCO₂ · D₂O and the observed fundamental bands have been discussed taking into account the⁶Li/⁷Li and H₂O/D₂O isotope wavenumber shifts on the fundamental vibrations.

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Infrarotspektren (700–200 cm^–1) und⁶Li/⁷Li- und H₂O/D₂O-Isotopeneffekte für vier isotopensubstituierte Lithiumformat-monohydrate

Zusammenfassung Die Infrarotspektren in der Region von 700–200 cm^–1 werden für⁶LiHCO₂ · H₂O,⁶LiHCO₂ · D₂O,⁷LiHCO₂ · H₂O und⁷LiHCO₂ · D₂O angegeben und die beobachteten Grundschwingungen zusammen mit den isotopischen Verschiebungen der Wellenzahlen diskutiert.

     

Physicochemical investigation of the ternary system KF-H2O2-H2O

Conclusions An investigation of the fusibility in the system KF-H₂O₂-H₂O confirmed the existence of KF · H₂O₂ and demonstrated the formation of a new compound, KF · 2H₂O₂, which exists in the system in the interval from –70 to 20° in the region of high hydrogen peroxide concentrations.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 491–494, March, 1973.     

Die Verfeinerung der Kristallstruktur von Li2Ge2O5

Zusammenfassung Die Kristallstruktur von Li₂Ge₂O₅ wird durchFourier- und Differenz-Fourier-Synthesen verfeinert. Als mittlere Atomabstände werden gefunden: Ge–O=1,71 und Li–O=1,96 Å.

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The crystal structure of Li₂Ge₂O₅ has been refined byFourier and difference syntheses. The average atomic distances are found to be: Ge–O=1,71 and Li–O=1,96 Å.

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Mit 1 Abbildung     

Gas-phase reactions in plasmas of SF6 with O2 in He

Processes which occur in microwave discharges of dilute mixtures of SF₆ and O₂ in He have been examined using a flow reactor sampled by a mass spectrometer. Two classes of experiments were performed. In the first set of experiments, mixtures containing 6×10¹¹ cm^–3 SF₆, 6×10¹⁶ cm^–3 He, and O₂ in the range (0–3.6)×10¹³ cm^–3 were passed through a 20-W 2450-MHz microwave discharge. The gas mixtures arriving at a sample point downstream from the discharge were examined for SF₆, SF₄, SOF₂, SOF₄, SO₂F₂, SO₂, F, and O. In the second class of experiments, rate coefficients were measured for the reactions of SF₄ with O and O₂ and for the reaction of SF with O. The rate coefficient for the reaction of SF with O was found to be (4.2±1.5)×10^–11 cm^–3 s^–1. SF₄ was found to react so slowly with both oxygen atoms and oxygen molecules that only upper limits could be placed on the rate coefficients for these reactions. These values were 2×10^–14 cm³ s^–1 and 5×10^–15 cm³ s^–1 for reactions with O and O₂ respectively. The observed distribution of products from the discharged mixtures is discussed in terms of the measured rate coefficients.     

The mutual diffusion coefficients of Na2SO4−H2O and MgSO4−H2O at 25°C from Rayleigh interferometry

The volume-fixed mutual diffusion coefficients of Na₂SO₄–H₂O and MgSO₄–H₂O have been measured, from dilute solutions to near saturation, to an accuracy of 0.1–0.2% by free-diffusion Rayleigh interferometry. These results are compared to other available diffusion data for these salts. The diffusion coefficients of Na₂SO₄–H₂O and MgSO₄–H₂O decrease regularly with increasing concentration, while those of many other salts exhibit both a maximum and a minimum as a function of concentration. A few diffusion coefficients have also been measured for KCl–H₂O.Reference to a company or product names does not imply approval or recommendation of the product by the University of California or the U.S. Department of Energy to the exclusion of others that may be suitable.This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights.University of Illinois at Urbana-Champaign; tenure served as a participating guest at Lawrence Livermore Laboratory.     

Heats of transport of some chlorides in H2O and D2O

Heats of transport of 0.01 m HCl, Me₄NCl, and Et₄NCl in H₂O and 0.01 m KCl, NaCl, and CsCl in D₂O were determined from the measurement of initial (homogeneous) and final (Soret steady state) thermoelectric powers of the thermocell (T)Ag–AgCl/Solution/AgCl–Ag(T+T) at a mean temperature of 25°C. The results are discussed in terms of ion-solvent interaction and properties of H₂O and D₂O.     

Radiolysis in H2O/D2O mixtures. Hydrogen production under LOCA simulation

The hydrogen isotope radiolytic yields, G(H₂), G(HD) and G(D₂) were determined in H₂O/D₂O mixtures under chemical conditions close to a LOCA in a PHWR like Atucha I Nuclear Station, that is 2·10^–3 MH₃BO₃ and p(H+D)=8.5±0.2. The total hydrogen radiolytic yield G(H₂+HD+D₂) as a function of the deuterium atom fraction goes through a flat maximum at about 0.58. This result in dicates that the 4% flammability limit for hydrogen in the reactor's containment with be reached sooner than what is expected assuming a linear combination of pure H₂ and D₂ radiolytic yields. Hydrogen radiolytic production in 10^–3 M KBr in H₂O/D₂O mixtures gives the same results as in the boric solutions suggesting a bimolecular B(OH) ₄ ^– +OH reaction. Identical isotope concentration factors were calculated for both solutions.     

Studies on synthesis, characterization and thermochemistry of Mg2[B2O4(OH)2]·H2O

A new magnesium borate Mg₂[B₂O₄(OH)₂]·H₂O has been synthesized by the method of phase transformation of double salt at hydrothermal condition and characterized by XRD, IR, TG and DSC. The enthalpy of solution of Mg₂[B₂O₄(OH)₂]·H₂O in 0.9764 mol L^–1 HCl was determined. With the incorporation of the enthalpies of solution of H₃BO₃ in HCl (aq), of MgO in (HCl+H₃BO₃) (aq), and the standard molar enthalpies of formation of MgO(s), H₃BO₃(s), and H₂O(l), the standard molar enthalpy of formation of –(3185.78±1.91) kJ mol^–1 of Mg₂[B₂O₄(OH)₂]·H₂O was obtained.This revised version was published online in November 2005 with corrections to the Cover Date.     

Untersuchungen an Kristallhydraten anorganischer Salze, 8. Mitt. Interpretation der Schwingungsspektren vonM(BF4)2·6H2O fürM=Fe2+, Co2+, Ni2+

The infrared and Raman spectra were recorded in the range 4000–160 cm^–1 forM(BF₄)₂·6 H₂O whereM=Fe²⁺, Co²⁺, Ni²⁺. The spectroscopic data support the X-ray structural data in showing that in the crystal hydrates studied two kinds of hydrogen bonds are present: H₂O...H₂O and OH₂... F₄B^–. The energies and molecular force constants (f _OH and fH₂O) andr _OH for OH₂...F₄B^– were calculated for the three crystal hydrates. It was found that the bond OH₂... F₄B^– is comparatively weak, with mean energy 3.7–3.3 kcal/mol. Two types of water molecule with different structures are existing as the first are participating in H₂O...H–O–H...F₄B^– and the second in BF₄ ^–...H–O–H...F₄B^–.     

Hydrolysis of [Pt(dien)H2O]2+ and [Pd(dien)H2O]2+ complexes in water

The hydrolysis of the [Pt(dien)H₂O]²⁺ and [Pd(dien)H₂O]²⁺ complexes has been investigated by potentiometry at 298 K, in 0.1 mol dm^–3 aqueous NaClO₄. Least-squares treatment of the data obtained indicates the formation of mononuclear and -hydroxo-bridged dinuclear complexes with stability constants: log ₁₁ = –6.94 for [Pt(dien)OH]⁺, log ₁₁ = –7.16 for [Pd(dien)OH]⁺, and also log ₂₂ = –9.37 for [Pt₂(dien)₂(OH)₂]²⁺ and log ₂₂ = –10.56 for [Pd₂(dien)₂(OH)₂]²⁺. At pH values > 5.5, formation of the dimer becomes significant for the Pt^II complex, and at pH > 6.5 for the Pd^II complex. These results have been analyzed in relation to the antitumor activity of Pt^II complexes.     

Kinetics of the thermal desorption of O2, HCl,and H2O from the surface of cobalt chromite

A study has been carried out on the kinetics of the temperature-programmed desorption of O₂, HCl, and H₂O from the surface of cobalt chromite. A mathematic model was obtained for the kinetics of the thermal desorption and a method was developed for determining the kinetic constants. The kinetic parameters of the desorption of O₂, HCl, and H₂O were calculated using these experimental data.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 29, No. 5, pp. 449–455, September–October, 1993.     

Thermodynamics of ionization of D2O and D2PO 4 −

The quotients for the ionization of D₂O and the neutralization of D₂PO ₄ ^– have been determined potentiometrically in 0.2m KCl from 50 to 300°C at the saturation pressure. By combination with the other data, analytical expressions for the dependence on temperature and ionic strength have been derived. Rounded values for the thermodynamic quantities for the ionization of D₂O and the neutralization of D₂PO ₄ ^– are given along with standard errors. The magnitude of the isotope effects is discussed in terms of the zero-point-energy approximation and the acid strength in light water.ORAU Summer Trainee Program 1973.     

The mutual diffusion coefficients of NaCl−H2O and CaCl2−H2O at 25°C from Rayleigh interferometry

The volume-fixed mutual diffusion coefficients of NaCl–H₂O and CaCl₂–H₂O have been measured to an accuracy of 0.1–0.2%, from dilute solutions to high concentrations, by free diffusion Rayleigh interferometry. These diffusion coefficients are compared to other diffusion data for these salts, obtained from Guoy interferometry and the conductometric method. Discrepancies between data in the literature are resolved using the present results. Some diffusion coefficients have also been measured for KCl–H₂O and NH₄Cl–H₂O.Work performed in part under the auspices of the U.S. Department of Energy by the Lawrence Livermore Laboratory under contract number W-7405-ENG-48.Reference to a company or product name does not imply approval or recommendation of the product by the University of California or the U.S. Department of Energy to the exclusion of others that may be suitable.This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights.University of Illinois at Urbana-Champaign; tenure served as a participating guest at Lawrence Livermore Laboratory.     

Formation Mechanism of O2– Radical Anions in the Adsorption of NO + O2 and NO2 + O2 Mixtures on ZrO2 According to EPR and TPD Data

The effects of various factors on the formation of O₂ ^– radical anions in the adsorption of an NO + O₂ or NO₂ + O₂ mixture on ZrO₂ were studied. It was found that the thermal stability of the O₂ ^– species depends on the composition of the adsorbed gas. It was suggested that nitrogen oxide complexes on ZrO₂ centers are responsible for the formation of O₂ ^–. These centers are formed upon the treatment of the oxide in a vacuum; however, they are different from both coordinatively unsaturated Zr⁴⁺ cations (NO adsorption centers at 77 K) and Zr⁴⁺–O^––O^––Zr⁴⁺ centers, at which O₂ ^– are formed because of the adsorption of H₂ + O₂. Based on the experimental data, the mechanism of O₂ ^– formation in the adsorption of an NO + O₂ mixture is discussed.     

Crystal and molecular structures of heteroligand bis(hexafluoroacetylacetonato)copper(II) complexes with 3-imidazoline nitroxyl radicals,Cu(C5HF6O2)2:L=1:1 (L1=C13H18N3O,L2=C8H15N2O)

Crystal structures were determined for two new derivatives of heteroligand complexes of Cu(C₅HF₆O₂)₂ with nitroxyl radicals derived from 3-imidazoline: Cu(C₅HF₆O₂)₂(C₁₃H₁₈N₃O) (I) and Cu(C₅HF₆O₂)₂(C₈H₁₅N₂O) (II). The unit cell parameters for I are as follows: a=10.555(3), b=15.505(5), c=18.509(6) Å, V = 3029(1) ų, Z=4, d_calc=1.57 g/cm³, space group P2₁2₁2₁. The unit cell parameters for II are as follows: a=16.018(3), b=15.886(3), c=19.665(4) Å, V = 5004(1)ų, Z=8, d_calc=1.68 g/cm³, d_exp=1.68 g/cm³, space group P2₁2₁2₁. The structure of I is molecular. The coordination of the copper ion is a trigonal bipyramid formed by two oxygen atoms of the (hfac) ions and the nitrogen atom of the imidazoline heterocycle in the equatorial plane [Cu–O, 1.91(7), 2.242(7) Å, Cu–N, 2.010(7) Å] and the other oxygen atoms of the (hfac) anion in the axial positions [Cu–O, 1.940(6), 1.963(6) Å]. Complex II is polymeric. The two crystallographically independent Cu(hfac)₂ fragments are linked in a chain by means of two L² ligands. The coordination of the copper ions is a square bipyramid, whose equatorial plane is formed by the oxygen atoms of the (hfac) anion [Cu–O, 1.89(1)–2.03(1) Å]. The axial positions are occupied by nitrogen atoms [Cu–N, 2.52(1), 2.40(1) Å] and an oxygen atom of the NO fragment [Cu–O, 2.96(1), 2.67(1) Å] of different L² ligands. The ...Cu(hfac)₂–L²–Cu(hfac)₂–L₂... chains in the unit cell are located at two levels (x1/4 and 3/4).Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Zhurnal Strukturnoi Khimii, Vol. 34, No. 2, pp. 126–133, March–April, 1993.     

Molybdenum phosphate glasses modified by Cu2O

Glasses in the system Cu₂O-P₂O₅-MoO₃ were prepared. The transformation temperature of glasses,T _g, ranges from 122 to 436°C and depends strongly on their composition.T _g values are mainly controlled by the oxygen-packing density. The structure of glasses was studied by infrared spectroscopy. The presence of various phosphate and molybdate units, from discrete monomeric to those with three-dimensional networks, has been observed. The electrical conductivity of prepared glasses depends mainly on Cu₂O content and varies from 10^–14–1cm^–1, for the glass free of Cu₂O, to 10^–6–1cm^–1, for glasses with compositions near of the binary Cu₂O-MoO₃ composition.This work was supported by grant No 1/731/94 of the Slovak Grant Agency for Science. The paper was presented on TERMANAL'94, XIII. International Conference on Thermal Analysis, October 1994, High Tatras, Slovakia.     

Remotely controlled on-line production of different species labeled with15O

For on-line production of [¹⁵O]–O₂, [¹⁵O]–CO₂, [¹⁵O]–CO, and [¹⁵O]–H₂O, a new apparatus was assembled. The yield at a beam current of 10 A and a flow rate of 750 ml min^–1 was about 110 MBq ml^–1 target gas or 93 MBq ml^–1 H₂O at steady state.     

Coincidence Mössbauer spectroscopic studies on57Co-labelled [CoFe2O(CH3CO2)6(H2O)3]

Coincidence Mössbauer spectra of⁵⁷Co-labelled [CoFe₂O(CH₃CO₂)₆(H₂O)₃] were determined at 78 K and 298 K with three timewindows of 0–50, 50–150 and 150–300 ns. Temperature dependence in the spectral shape ascribed to an intramolecular electron transfer was observed in all the time-window spectra, while little time dependence was observed. The results indicate that⁵⁷Fe atoms produced by EC-decay are incorporated in a chemical environment similar to that of the parent⁵⁷Co atoms, forming a trinuclear Fe^IIFe₂ ^III structure at an early stage after the EC-decay.after April 1, 1991.