Showing papers in "Journal of Physical and Chemical Reference Data in 1979"

Rate Constants for Reactions of Inorganic Radicals in Aqueous Solution

Abstract: Rate constants have been compiled for reactions of various inorganic radicals produced by radiolysis or photolysis, as well as by other chemical means in aqueous solutions. Data are included for the reactions of ⋅CO2 −, ⋅CO3⋅−, O3, ⋅N3, ⋅NH2, ⋅NO2, NO3⋅, ⋅PO32−, PO4⋅2−, SO2⋅ −, ⋅SO3 −, SO4⋅−, ⋅SO5⋅−, ⋅SeO3⋅ −, ⋅(SCN)2⋅ −, ⋅CL2⋅−, ⋅Br2⋅ −, ⋅I2⋅ −, ⋅ClO2⋅, ⋅BrO2⋅, and miscellaneous related radicals, with inorganic and organic compounds.

Atomic radiative and radiationless yields for K and L shells

Abstract: The available body of information on (a) fluorescence, Auger, and Coster‐Kronig yields, (b) radiative and radiationless transition rates, (c) level widths, (d) x‐ray and Auger line widths, (e) x‐ray and Auger spectra, and (f) Coster‐Kronig energies has been used to generate an internally consistent set of values of atomic radiative and radiationless yields for the K shell (5 ?Z?110) and the L subshells (12 ?Z?110). Values of fluorescence yields ωk, ω1, ω2, ω3, Coster‐Kronig yields F1, F1.2, F1.3, F1.3, F2.3. Auger yields ak, a1, a2, a3, and effective fluorescence yields ν1 and ν2 are presented in tables and graphs. Estimates of uncertainties are given. Updated and expanded graphs of partial and total widths of K, L1, L2, and L3 levels are presented as well as a reference list of papers published since about 1972.

Natural widths of atomic K and L levels, Kα X‐ray lines and several KLL Auger lines

Abstract: Semi‐empirical values of the natural widths of K, L1, L2, and L3 levels, Kα1 and Kα2 x‐ray lines, and KL1L1, KL1L2 and KL2L3 Auger lines for the elements 10?Z?110 are presented in tables and grapahs. Level width Γi (i=K, L1,L2, L3) is obtained from the relation Γi=ΓR,i/ωi, using the theoretical radiative rate ΓR,i from Scofield’s relativistic, relaxed Hartree‐Fock calculation and the fluorescence yield ωi from Krause’s evaluation. X‐ray and Auger lines widths are calculated as the sums of pertinent level widths. This tabulation of natural level and line widths is internally consistent, and is compatible with all relevant experimental and theoretical information. Present semi‐empirical widths, especially those of Kα1 and Kα2 x‐rays, are compared with measured widths. Uncertainties of semi‐empirical values are estimated.

Electrical resistivity of copper, gold, palladium, and silver

Abstract: In this work, recommended values for the electrical resistivity as a function of temperature from the cryogenic region to well beyond the melting point are given for bulk pure copper, gold, palladium, and silver. In addition to the total electrical resistivity values for the solid state, intrinsic electrical resistivity values are presented from cryogenic temperatures to the melting point. The values are corrected for the change in geometry due to thermal expansion. The recommendations are based on theoretical considerations and on the experimental data found in the open literature. That available experimental data together with information pertaining to the specimen characterization and measurement conditions are included in this work. The methods of data evaluation and other considerations used in arriving at the recommendations are described. For the solid state, an interpolation scheme is given to aid in the determination of values between those supplied in the tables; for the liquid state, equations ...

Molecular structures of gas‐phase polyatomic molecules determined by spectroscopic methods

Abstract: Spectroscopic data related to the structures of polyatomic molecules in the gas phase have been reviewed, critically evaluated, and compiled. All reported bond distances and angles have been classified as equilibrium (re), average (rz), substitution (rs), or effective (ro) parameters, and have been given a quality rating which is a measure of the parameter uncertainty. The surveyed literature includes work from all of the areas of gas‐phase spectroscopy from which precise quantitative structural information can be derived. Introductory material includes definitions of the various types of parameters and a description of the evaluation procedure.

Relativistic atomic form factors and photon coherent scattering cross sections

Abstract: Tabulations are presented of relativistic Hartree‐Fock atomic form factors F (x,Z), for values of x (=sin(ϑ/2)/λ from 0.01 to 109 A−1, for all elements Z=1 to 100. For Z=1, F (x,Z) is given by the exact expression of Pirenne. For Z=2 to 98, x=0.01 to 2.0 A−1, the tabulated values are those of Cromer and Waber given in the International Tables for X−Ray Crystallography (Vol. IV, 1974), based in part on the work of Doyle and Turner. For Z=21 to 92, x=2.2 to 6.0 A−1, the present tables are based on the values of Doyle and Turner and additional values (Z=44,60,68, and 74) as given by O/verbo/. For Z=3 to 20.x=2.2 to 45 A−1, Z=21 to 92,x=62 to 45 A−1 the tables are interpolated from values given for 36 elements by O/verbo/, extended to x=109 A−1 using O/verbo/’s corrections to the Bethe‐Levinger K‐shell expression. The remainder of the table is filled in by interpolation and extrapolation, guided for high x‐values by the Bethe‐Levinger result. Tables of relativistic coherent (Rayleigh) scattering cross sections, obtained by numerical integration of the Thomson formula weighted by F2(x,Z), are presented for all elements Z=1 to 100, for photon energies 100 eV (λ=124 A=12.4 nm) to 100 MeV (λ=0.000 124 A=12.4 fm). Departures from the nonrelativistic coherent scattering cross sections tabulated in J. Phys. Chem. Ref. Data 4, 471 (1975) are less than 1% for Z<20. However for a high‐Z element such as lead, for example, the relativistic coherent scattering cross section is systematically higher by less than 0.4% below 1 keV, by 8% at 100 keV and by 13% above 1 MeV.

Critically evaluated rate constants for gaseous reactions of several electronically excited species

Abstract: An extensive evaluation is presented of the available gas phase chemical kinetic rate constants for the interactions of the low lying electronic states of several atoms and molecules with numerous collision partners. These include the following excited states: C(21D2,21S0), N(22D3/2,5/2,22P1/2,3/2), P(32D3/2,5/2,32P1/2,3/2,), S(31D2,31S0). Se(43P0,41D2,41S0), Te(53P1,0,51D2,51S0), CO(a3Π,a′3Σ+,d3Δ,e3Σ−,A1Π), CS(a3Π,A1Π), OH(A2Σ+), OD(A2Σ+), O2(c1Σu−,C3Δu,A3Σu+,B3 Σu−), and S2(a1Δg,b1Σg+,A3Σu+, B3Σu−). Wherever possible, recommended values are suggested. Much of the data refers only to room temperature. To facilitate the evaluation, collision‐free radiative lifetimes often have been required. These also have been evaluated and are presented. The mechanisms of the interactions and the various potential kinetic channels are discussed. These include such processes as chemical reactions, electronic quenching to the ground electronic state, electronic cross relaxation to an adjacent excited state, and for molec...

Energy Levels of Aluminum, Al I through Al XIII,

Abstract: Energy level data are given for the atom and all positive ions of aluminum (z=13). These data have been critically compiled, mainly from published material on measurements and analyses of the optical spectra. We have derived or recalculated the levels for a number of the ions. In addition to the level value in cm−1 and the parity, the J value and the configuration and term assignments are listed if known. Leading percentages from the calculated eigenvectors are tabulated wherever available. Ionization energies are given for all spectra.

Energy Levels of Calcium, CA I through CA XX,

Abstract: The energy levels of the calcium atom in all of its stages of ionization, as derived from the analyses of atomic spectra, have been critically compiled. In cases where only line classifications are reported in the literature, level values have been derived. Electron configurations, term designations, J‐values, experimental g‐values, and ionization energies are included. Calculated percentages of the two leading components of the eigenvectors of the levels are given.

Energy levels of titanium, Ti I through Ti XXII

Abstract: The energy levels of the titanium atom in all of its stages of ionization, as derived from the analyses of atomic spectra, have been critically compiled. In cases where only line classifications are reported in the literature, level values have been derived. Term designations, experimental g‐values, and ionization energies are included. Calculated percentages of the two leading components of eigenvectors of the levels are given.

Evaluated activity and osmotic coefficients for aqueous solutions: bi‐univalent compounds of lead, copper, manganese, and uranium

Abstract: A critical evaluation of the mean activity and osmotic coefficients in aqueous solutions of twelve bi‐univalent compounds of lead, copper, manganese and uranium at 298.15 K is presented. Osmotic coefficients were calculated from direct vapor pressure measurements, from isopiestic measurements and and from freezing point depression measurements. Activity coefficients were calculated from electromotive force measurements on galvanic cells without transference. Given are empirical coefficients for three different correlating equations, obtained by a weighted least squares fit of the experimental data, and tables consisting of the activity coefficients of the compounds, the osmotic coefficients and activity of water, and the excess Gibbs energy of the solution as functions of the molality for each electrolyte system. The literature coverage is through the computerized version of Chemical Abstracts of April 1979.

A correlation of the viscosity and thermal conductivity data of gaseous and liquid propane

Abstract: Data for the viscosity and thermal conductivity of gaseous and liquid propane have been evaluated and represented by empirical functions developed in previous work. Tables of values are presented for the range 140–500 K for pressures to 50 MPa (? 500 atm). The viscosities are estimated to have uncertainties of about ±5%, with corresponding uncertainties of the thermal conductivities of about ±8%. It is stressed that the data base should be improved. As in our work with other fluids, the anomalous contribution to the thermal conductivity in the vicinity of the critical point is included.

Energy levels of potassium, K I through K XIX

Abstract: Data on the energy levels of the potassium atom in all of its stages of ionization, as derived from the analyses of atomic spectra, have been critically compiled. In cases where only line classifications are reported in the literature, level values have been derived. Electron configurations, term designations, J‐values, experimental g‐values, and ionization energies are included.

The spectrum and energy levels of the neutral atom of boron (Bi)

Abstract: The published data on the spectrum of the neutral atom of boron are complied and presented. In one table 164 lines in the range 36010−993 A are listed with their intensities and classifications. A second table gives 92 levels with the numerical values of the energy.

Microwave spectra of molecules of astrophysical interest. XVIII. Dimethyl ether

Abstract: The microwave spectra of dimethyl ether (methoxymethane) is critically reviewed and supplemented through calculations which include the contributions of internal rotation and centrifugal distortion in the molecular Hamiltonian. The primary objective of this review is to provide microwave spectral transitions applicable to molecular radio astronomy for the ground vibrational state rotational spectrum of the most abundant isotopic form of dimethyl ether, 12CH316O12CH3. While all measured rotational transitions are included, the predicted transition frequencies were limited to J?15 in the range 1 GHz to 300 GHz. In order to provide a complete summary of the laboratory studies on dimethyl ether, the rotational constants of the less abundant isotopic species and excited torsional states are also tabulated and all reported rotational studies are referenced.

Microwave spectra of molecules of astrophysical interest. XVI. Methyl formate

Abstract: The microwave spectrum of methyl formate is critically reviewed for information applicable to radio astronomy. The review is based on new laboratory measurements in the frequency range from 8 GHz to 58 GHz. Molecular data such as the derived rotational constants, centrifugal distortion parameters, internal rotation parameters, electric dipole moment and molecular structure are tabulated. Since the primary objective is to provide microwave spectral transitions applicable to radio astronomy observations, the review encompasses only the ground state rotational spectrum of the most abundant isotopic form of methyl formate, H12C16O2CH3. While all measured transitions are included, the predicted transitions were limited to J?12 in the range of 900 MHz to 250 GHz.

Electrical resistivity of alkali elements

Abstract: This paper presents and discusses the available data and information on the electrical resistivity of alkali elements (lithium, sodium, potassium, rubidium, cesium, and francium) and contains recommended reference values (or provisional or typical values). The compiled data include all the experimental data available from the literature and cover the temperature dependence, pressure dependence, and magnetic flux density dependence. The temperature range covered by the compiled data is from cryogenic temperatures to above the critical temperature of the elements. The recommended values are generated from critical evaluation, analysis, and synthesis of the available data and information and are given for both the total electrical resistivity and the intrinsic electrical resistivity. For most of the elements, the recommended values cover the temperature range from 1 K to 2000 K.

Evaluated activity and osmotic coefficients for aqueous solutions: iron chloride and the bi‐univalent compounds of nickel and cobalt

Abstract: A critical evaluation of the mean activity and osmotic coefficients in aqueous solutions of iron chloride, nickel chloride, perchlorate, and nitrate and twenty‐nine bi‐univalent compounds of cobalt at 298.15 K is presented. Osmotic coefficients were calculated from direct vapor pressure measurements, from isopiestic measurements, from freezing point depression measurements, and from vapor pressure osmometry measurements. Given are empirical coefficients for three different correlating equations, obtained by a weighted least squares fit of the experimental data, and tables consisting of the activity coefficients of the compounds, the osmotic coefficients and activity of water, and the excess Gibbs energy of the solution as functions of the molality for each electrolyte system. The literature coverage is through the computerized version of Chemical Abstracts of April 1979.

Molten Salts: Volume 4, Part 4 Mixed Halide Melts Electrical Conductance, Density, Viscosity, and Surface Tension Data

Abstract: Data on the electrical conductance, density, viscosity, and surface tension of mixed halide melts have been systematically collected and evaluated. Results are given for eighty‐five binary mixtures over a range of compositions and temperatures.

Vapor Pressures and Boiling Points of Selected Halomethanes

Abstract: This critical review is a study of the vapor pressure–boiling point data from the triple point to the critical point for CH4–a Xa (X=Br, I) and CH4−(a+b+c+d) FaClbBrcId halomethanes. The available data are carefully analyzed and the ’’best’’ data selected. The selection procedure is discussed. Uncertainties in the selected temperatures and pressures are reported. The selected data were fitted to the Antoine equation for data up to 1500 mm Hg pressure and the Wagner equation for data up to the critical point. Antoine constants for nineteen compounds and the Wagner constants for five compounds are reported. The enthalpy of vaporization at 298.15 K and at the normal boiling point have been computed.

Microwave spectra of molecules of astrophysical interest XIV. Vinyl cyanide (acrylonitrile)

Abstract: The available data of the microwave spectrum of vinyl cyanide are critically reviewed and tabulated. Molecular data such as rotational constants, centrifugal distortion constants, hyperfine coupling constants, dipole moments, and structural parameters are tabulated. Rotational transitions from 400 MHz to 200 GHz, which are likely to be of interest to radio astronomy, are calculated and tabulated along with their estimated 95% confidence limits.

Microwave spectra of molecules of astrophysical interest XV. Propyne

Abstract: The microwave spectrum of propyne is critically reviewed for information applicable to radio‐astronomy. Molecular data such as the derived rotational constants, centrifugal distortion parameters, hyperfine coupling constants, electric dipole moment, and molecular structure are tabulated. The observed rotational transitions are presented for the astronomically interesting isotopic forms and the lowest lying vibrational state of propyne. Calculated rotational transitions are presented for the ground vibrational state of 12CH3 12C≡ 12CH, 13CH3 12C≡ 12CH, 12CH313C≡ 12CH and 12CH3 12C≡ 13CH, and for the vibrationally excited state ν10 of 12CH3 12C≡ 12CH.

Electrical resistivity of alkaline earth elements

Abstract: This paper presents and discusses the available data and information on the electrical resistivity of alkaline earth elements (beryllium, magnesium, calcium, strontium, barium, and radium) and contains recommended or provisional reference values. The compiled data include all the experimental data available from the literature. The temperature range covered by the compiled data is from cryogenic temperatures to above the melting temperature of the elements. The recommended values are generated from critical evaluation, analysis, and synthesis of the available data and information and are given for both the total electrical resistivity and the intrinsic electrical resistivity. For most of the elements, the recommended values cover the temperature range from 1 K to 1000 K.

A review, evaluation, and correlation of the phase equilibria, heat of mixing, and change in volume on mixing for liquid mixtures of methane + propane

Abstract: The available experimental data for liquid‐vapor equilibria, heat of mixing, and change in volume on mixing for the methane+ethane system have been reviewed and where possible evaluated for consistency. The derived properties chosen for analysis and correlation were liquid mixture excess Gibbs energies, Henry’s constants, and K values. Data sets, selected on the basis of the consistency tests applied, were correlated as functions of temperature and composition to provide internally consistent sets of property values suitable for engineering design calculations.

Ideal gas thermodynamic properties of selected bromoethanes and iodoethane

Abstract: The available molecular parameters, fundamental frequencies, potential barrier heights, torsional frequencies, and standard enthalpies of formation at 298.15 K for selected bromoethanes and iodoethane containing one symmetric‐top group have been critically evaluated and recommended values selected. The chemical thermodynamic properties in the ideal gas state at one atmosphere pressure using the rigid‐rotor harmonic‐oscillator approximation have been calculated for CH3CH2Br, CH3CHBr2, CH3CBr3 C2Br6, and CH3CH2I. The internal rotational contributions have been obtained from the partition function formed by the summation of internal rotation energy levels.

Thermodynamic properties of normal and deuterated naphthalenes

Abstract: Structural and spectroscopic data and the standard enthalpy of formation 298.15 K for C10H8, α‐C10H1D4, β‐C10H4D4 and C10D8 were reviewed. The selected values were utilized to calculate the ideal gas thermodynamic properties in the temperature range 0 to 1500 K, using the rigid rotor and harmonic oscillator model. The comparison between the third law entropies and the spectroscopically calculated entropies of C10H8 was studied. The agreement is satisfactory within the experimental uncertainties.

Comments Simplification of thermodynamic calculations through dimensionless entropies

Abstract: The advantages of using thermodynamic quantities divided by the gas constant (H/R, G/R, etc,) in calculations are described. It is recommended that thermodynamic tables be presented in this form, so that the entries are either dimensionless or in units of kelvins.