Showing papers in "Journal of Physical and Chemical Reference Data in 1978"

Viscosity of Liquid Water in the Range - 8 C to 150 C,

Abstract: The paper re‐analyzes the results of earlier, very precise measurements of the viscosity of water at essentially atmospheric pressure. This is done in terms of a new, theoretically‐based equation for the operation of a capillary viscometer rather than in terms of semi‐empirical equations used by the original authors. The new analysis eliminates possible systematic errors and permits the establishment of realistic error bounds for water in its role as a standard reference substance for viscosity. The latter are smaller than those embodied in the most recent International Formulation. Standard values of the ratio of viscosity at a temperature T to its value at 20 °C have been derived from the re‐analyzed data because the uncertainty of this ratio is an order of magnitude smaller than that of the absolute values. The ratios are used to generate absolute values with the aid of the standard NBS datum μ=1002.0 μPa s at 20 °C. The viscosity ratios have been correlated with the aid of two empirical equations. The more accurate equation covers the range 0 °C?t ?40 °C with an uncertainty of ±0.05%. The less accurate equation covers the wider range −8 °C?t?150 °C with the more limited accuracy of ±0.2%. The two empirical equations are compatible with each other to 0.09%.

Critical review of hydrolysis of organic compounds in water under environmental conditions

Abstract: This review examines the rate constants for hydrolysis in water of 12 classes of organic compounds with the objective of using these data to estimate the persistence of these compounds in freshwater acquatic systems. Primary data were obtained by literature review through most of 1975 and some of 1976. These data, which include values for acid, base, and water promoted rate constants (kA, kB, kN) and temperature coefficients are presented in 18 tables in section 4. Estimated rate constants for hydrolysis under environmental conditions are presented in 13 tables in section 5, including rate constants at 298 K and pH 7 for acid, base, and water promoted reactions together with values for the estimated rate constant (kh) and the half‐life (t1/2).

JANAF thermochemical tables, 1978 supplement

Abstract: The thermodynamic tabulations previously published in NSRDS–NBS 37, the 1974 Supplement (J. Phys. Chem. Ref. Data 3, 311 (1974), and the 1975 Supplement (J. Phys. Chem. Ref. Data 4, 1 (1975) are extended by 131 new and revised tables. The JANAF Thermochemical Tables cover the thermodynamic properties over a wide temperature range with single phase tables for the crystal, liquid, and ideal gas state. The properties given are heat capacity, entropy, Gibbs energy function, enthalpy, enthalpy of formation, Gibbls energy of formation, and the logarithm of the equilibrium constant for formation of each compound from the elements in their standard reference states. Each tabulation lists all pertinent input data and contains a critical evaluation of the literature upon which these values are based. Literature references are given.

Thermodynamic Properties of Ammonia

Abstract: An analytic thermodynamic surface has been fitted to the experimental data for ammonia for the temperature range extending from the triple point to 750 kelvins and for the pressure range extending from the dilute gas to 500 MPa (5000 bar). Values for the thermodynamic properties are tabulated at closely spaced intervals. A major part of the correlation was devoted to a study of the extent to which thermodynamic inconsistencies degrade the accuracy of the derived properties. This study focused as much on methods for correlating the data as on the data themselves. As a consequence, we are able to assign close tolerances to the tabulated thermodynamic properties over the range of the surface, including properties for the coexisting phases and even close to the liquid‐vapor critical point.

Evaluated activity and osmotic coefficients for aqueous solutions: The alkaline earth metal halides

Abstract: A critical evaluation of the mean activity and osmotic coefficients in aqueous solutions of the alkaline earth metal halides at 298.15 K is presented. Osmotic coefficients were calculated from direct vapor pressure measurements, from isopiestic measurements, and from freezing point depression measurements. Activity coefficients were calculated from electromotive force measurements on galvanic cells, both with and without transference, and from diffusion data. 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 halides, the osmotic coefficients and activity of water, and the excess Gibbs energy of the solution as a function of the molality for each electrolyte system. The literature coverage is through September 1976.

Thermal conductivity of ten selected binary alloy systems

Abstract: This work reviews and discuss the available data and information on the thermal conductivity of ten selected binary alloy systems and presents the recommended values resulting from critical evaluation, analysis, and synthesis of the available data. The ten binary alloy systems selected are the systems of aluminum‐copper, aluminum‐magnesium, copper‐gold, copper‐nickel, copper‐palladium; copper‐zinc, gold‐palladium, gold‐silver, iron‐nickel, and silver‐palladium. The recommended values given include values of the total thermal conductivity, electronic thermal conductivity, and lattice thermal conductivity. The uncertainty of the values is generally of the order of ±10%. The values for each of the alloy systems except two are given for 25 alloy compositions: 0.5, 1, 3, 5, 10(5)95,97,99, and 99.5%. For most of the alloy compositions, the values cover the temperature range from 4 K to the solidus temperature or 1200 K. In addition, reliable methods for the estimation of the electronic and lattice thermal conductivities of alloys have been developed in this study.

Ideal gas thermodynamic properties of methanoic and ethanoic acids

Abstract: The thermodynamic properties (H0−H00, (G0−H00)/T, (H0−H00)/T, S0, Cp0, ΔHf0, ΔGf0, and log Kf] for methanoic (formic) and ethanoic (acetic) acid monomers and dimers in the ideal gaseous state over the temperature range from 0 to 1500 K and 1 atm have been calculated by the statistical thermodynamic method using the most recent and reliable molecular and spectroscopic constants. The internal rotational contributions of −OH and −CH3 rotors to the thermodynamic properties were evaluated based on internal rotation partition functions formed by summation of calculated internal rotation energy levels. On an assumption that the vapor contains only monomers and dimers, the thermodynamic properties for the monomer‐dimer equilibrium mixture of methanoic and ethanoic acids in ideal gaseous state were derived. The results are in agreement with available experimental data.

Atomic transition probabilities for vanadium, chromium, and manganese (a critical data compilation of allowed lines)

Abstract: Atomic transition probabilities for about 2700 spectral lines of the elements vanadium, chromium, and manganese through all stages of ionization have been critically evaluated and compiled. All available literature sources have been utilized. Systematic trends along isoelectronic sequences have been extensively exploited to predict oscillator strengths (f‐values) whenever no data were available in the literature. The data are presented in separate tables for each element and stage of ionization and are arranged according to multiplets and, when appropriate, also to transition arrays and increasing quantum numbers. For each line, the transition probability for spontaneous emission, the absorption oscillator strength, and the line strength are given, along with the spectroscopic designation, the wavelength, the statistical weights, and the energy levels (when available) of the upper and lower atomic states. In addition, the estimated accuracy and the literature reference are indicated. In short introduction...

Microwave spectra of molecules of astrophysical interest XIII. Cyanoacetylene

Abstract: The microwave spectrum of cyanoacetylene 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 low‐lying vibrational states of cyanoacetylene. Calculated rotational transitions up to 300 GHz are presented for the ground vibrational state of H12C12C12C14N, H13C12C12C14N, H12C13C12C14N, H12C13C14N, HPu12C12C12C15N, and D12C12C12C14N, and for the vibrationally excited states ν5, ν6, ν7, 2ν7, and 3ν7 of H12C12C12C14N.

Energy levels of vanadium, V I through V XXIII

Abstract: The energy levels of the vanadium 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 given in the literature, level values have been derived. The percentages for the two leading components of the calculated eigenvectors of the levels are given where available. Ionization energies and experimental g‐values are also given.

Semi‐empirical extrapolation and estimation of rate constants for abstraction of H from methane by H, O, HO, and O2

Abstract: It has been concluded that for extrapolating rate constants of atom transfer reactions to and from high temperatures, a useful form of the rate constant is k=AT2 exp(−C/T), where A and C are fitted constants. For k/[cm3/(mol s)] and TK, on the basis of previous experimental data, the values of log A and C for the following reactions are: H+CH4=H2+CH3, log A=7.15, C=4449; O+CH4=OH+CH3 log A=6.71, C=3240; HO+CH4 =H2O+CH3, log A=6.93, C=1485 and O2+CH4=O2H+CH3, log A=6.93, C=26153. At all temperatures, abstraction by HO is faster than by O. The form of the rate constant is equivalent to assuming that ΔCp 0‡, the heat capacity at the constant pressure of activation, is zero. When ΔCp O‡, was estimated and assumed to be constant (in principle, a more accurate assumption than ΔCp O‡ =0), the fit to the experimental data was slightly worse. It is confirmed that at 400 to 700 K, the kinetic and thermodynamic equilibrium constants for the reaction H+CH4 =H2+CH3 are significantly different. (At 1340 K, they are in agreement.)

Review of vibrational data and force field constants for polyethylene

Abstract: The results of a critical review of vibrational data, their assignments, and force field constants of polyethylene and the related homologous series of n‐alkanes are presented. The vibrational frequencies derived from Raman spectroscopy, infrared spectroscopy, and neutron inelastic scattering were collected from the literature. We have reviewed the vibrational band assignments starting from the comprehensive treatment of the n‐alkanes by Schachtschneider and Snyder [1,2]1 and including subsequent reassignments. Theoretical calculations of the vibrational frequencies were reviewed with emphasis on the various models used for molecular structure and force fields. Lattice dynamical calculations of polyethylene were performed using a valence force field for intramolecular interactions and a force field derived from a nonbonded atom‐atom potential function for intermolecular interactions. The molecular and lattice structural parameters were taken from x‐ray and neutron diffraction studies of polyethylene and s...

Microwave spectra of molecules of astrophysical interest XII. Hydroxyl radical

Abstract: The available data on the microwave spectrum of the hydroxyl radical are critically reviewed for information applicable to radio astronomy Molecular properties such as the rotational constants, spin‐orbit, spin‐spin and hyperfine coupling constants and centrifugal distortion parameters employed in or derived from the analysis are tabulated All the observed and predicted transitions of 16OH, 16OD, and 18OH below 300 GHz and lower state energy levels less than 4000 cm−1 are presented for the ground vibrational state The laboratory data on 17OH is included, but no predicted transitions are presented due to the limited data available In addition to the transition frequencies the table contains the calculated line strengths and energies of the levels involved in the transition An extensive bibliography of laboratory and astronomical studies of the hydroxyl radical is presented as an aid to workers in both fields

Tables of atomic spectral lines for the 10000 Å to 40000 Å region

Abstract: This compilation of atomic spectral lines for the 10000 A to 40000 A region tabulates 8885 selected lines, belonging to 57 elements, extracted from computer based data records. The tables are divided into three sections. In section I the strong lines in the 10000 A to 25000 A range are listed for 27 elements. Section II is a table of classified and unclassified lines, arranged in order of increasing vacuum wavenumber. Section III consists of vacuum wavenumber tables, with appropriate energy level and J values for the classified lines, listed by element. Detailed explanation of the data and sources used for the compilation are given.

Ideal gas thermodynamic properties of CH4−(a+b+c+d)FaClbBrcId Halomethanes

Abstract: The available molecular parameters, fundamental frequencies, and enthalpies of formation at 298.15K (ΔHf ° (298) for halomethanes of the type CH4−(a+b+c+d)FaClbBrcId have been critically evaluated and recommended values selected. Molecular parameters and ΔHf ° (298) for some halomethanes have been estimated as the experimental values for these compounds are not available. This information has been utilized to calculate the ideal gas thermodynamic properties Cp°, S°, H°−H°0,−(G°−H0°)/T, ΔHf °, ΔGf °, and logKf from 0 to 1500 K and at a pressure of one atmosphere using the rigid rotor‐harmonic oscillator approximation for the following compounds: CH2FBr, CH2ClBr, CH2CH, CH2BrI, CHF2Br, CHFClBr, CHFBr2, CHCl2Br, CHClBr2, CF3Br, CF3I, CF2ClBr, CF2Br2, , CF2I2, CFCl2Br, CFClBr2, CFBr3, CCl2Br, CCl3I, CCl2Br2, CClBr3.

Recommended atomic electron binding energies, 1s to 6p3/2, for the heavy elements, Z=84 to 103

Abstract: Recent experimental measurements of atomic electron binding energies, 1s to 6p3/2, for certain of the transuranic elements are incorporated into interpolation and extrapolation procedures yielding new recommendations for the electron binding energies from Z=84 to 103.

Ideal gas thermodynamic properties of phenol and cresols

Abstract: The standard chemical thermodynamic properties of phenol, o‐cresol, and m‐cresol, and p‐cresol were calculated by use of the rigid rotor harmonic oscillator approximation. The partition functions for internal rotation of ‐OH and ‐CH3 groups were calculated as a direct sum over the internal rotation energy levels. It was assumed that o‐cresol is a mixture of two rotational isomers. Values of molecular parameters, fundamental frequencies, potential barriers to internal rotation and enthalpies of formation were selected from among those reported in the literature and from some additional molecular orbital calculations.

The molar volume (density) of solid oxygen in equilibrium with vapor

Abstract: Data from the literature on the molar volume of solid oxygen have been compiled and critically analyzed. A correlated and thermodynamically consistent set of molar volumes, including the volume changes at the various solid phase transitions, is presented. Evidence for the existence of a δ‐solid phase is reviewed. Uncertainties in the data and in the recommended set of values are discussed.

Densities of Liquid CH(4-aXa (X=Br,i)) and CH(4-(a+b+c+d)) FaClbBrcId Halomethanes,

Abstract: The available density data for the air‐saturated liquid and for the liquid at its saturation vapor pressure have been critically reviewed and the ’’best’’ data selected for the following halomethanes: CHF2Cl, CHFCl2, CF3Cl, CF3Br, CF2Cl2, CFCl3, (data up to the critical point are available for these compounds); CH3Br, CH2Br2, CHBr3, CBr4, CH2I2, CH2FCl, (data up to the normal boiling point are available for these compounds); CHCl2Br (data over a small temperature range); CHI3, CI4, CH2Fl, CH2ClBr, CH2CH, CHF2Br, CHF2I, CHFBr2, CHFI2, CHCl2I, CHClBr2, CHClI2, CF3I, CF2Br2, CFBr3, CCl3Br, CCl3I, (few scattered data points are available for these compounds). The literature survey is complete up to June 1974. Selection of ’’best’’ data was arrived at by carefully evaluating each set of data for its accuracy, method of experimentation, sample purity, etc. The selection procedure is discussed. The uncertainty in the selected values is reported. For interpolation and limited extrapolation, the selected density data for each compound have been correlated through simple equations in temperature. The regression errors and the computed regression constants are reported in tables 2 and 4, respectively.