Journal of Physical and Chemical Reference Data

Dữ liệu động học cho các gốc tự do H⋅ và ⋅OH trong dung dịch nước, và các anion gốc tự do tương ứng, ⋅O− và eaq−, đã được phân tích kỹ qua phương pháp xung bức, xung quang học và các phương pháp khác. Hằng số tốc độ cho hơn 3500 phản ứng đã được lập bảng, bao gồm phản ứng với phân tử, ion và các gốc tự do khác có nguồn gốc từ các chất tan vô cơ và hữu cơ.

This work reviews the available data on thermodynamic properties of carbon dioxide and presents a new equation of state in the form of a fundamental equation explicit in the Helmholtz free energy. The function for the residual part of the Helmholtz free energy was fitted to selected data of the following properties: (a) thermal properties of the single-phase region (pρT) and (b) of the liquid-vapor saturation curve (ps, ρ′, ρ″) including the Maxwell criterion, (c) speed of sound w and (d) specific isobaric heat capacity cp of the single phase region and of the saturation curve, (e) specific isochoric heat capacity cv, (f) specific enthalpy h, (g) specific internal energy u, and (h) Joule–Thomson coefficient μ. By applying modern strategies for the optimization of the mathematical form of the equation of state and for the simultaneous nonlinear fit to the data of all these properties, the resulting formulation is able to represent even the most accurate data to within their experimental uncertainty. In the technically most important region up to pressures of 30 MPa and up to temperatures of 523 K, the estimated uncertainty of the equation ranges from ±0.03% to ±0.05% in the density, ±0.03% to ±1% in the speed of sound, and ±0.15% to ±1.5% in the isobaric heat capacity. Special interest has been focused on the description of the critical region and the extrapolation behavior of the formulation. Without a complex coupling to a scaled equation of state, the new formulation yields a reasonable description even of the caloric properties in the immediate vicinity of the critical point. At least for the basic properties such as pressure, fugacity, and enthalpy, the equation can be extrapolated up to the limits of the chemical stability of carbon dioxide. Independent equations for the vapor pressure and for the pressure on the sublimation and melting curve, for the saturated liquid and vapor densities, and for the isobaric ideal gas heat capacity are also included. Property tables calculated from the equation of state are given in the appendix.

In 1995, the International Association for the Properties of Water and Steam (IAPWS) adopted a new formulation called “The IAPWS Formulation 1995 for the Thermodynamic Properties of Ordinary Water Substance for General and Scientific Use”, which we abbreviate to IAPWS-95 formulation or IAPWS-95 for short. This IAPWS-95 formulation replaces the previous formulation adopted in 1984. This work provides information on the selected experimental data of the thermodynamic properties of water used to develop the new formulation, but information is also given on newer data. The article presents all details of the IAPWS-95 formulation, which is in the form of a fundamental equation explicit in the Helmholtz free energy. The function for the residual part of the Helmholtz free energy was fitted to selected data for the following properties: (a) thermal properties of the single-phase region (pρT) and of the vapor–liquid phase boundary (pσρ′ρ″T), including the phase-equilibrium condition (Maxwell criterion), and (b) the caloric properties specific isochoric heat capacity, specific isobaric heat capacity, speed of sound, differences in the specific enthalpy and in the specific internal energy, Joule–Thomson coefficient, and isothermal throttling coefficient. By applying modern strategies for optimizing the functional form of the equation of state and for the simultaneous nonlinear fitting to the data of all mentioned properties, the resulting IAPWS-95 formulation covers a validity range for temperatures from the melting line (lowest temperature 251.2 K at 209.9 MPa) to 1273 K and pressures up to 1000 MPa. In this entire range of validity, IAPWS-95 represents even the most accurate data to within their experimental uncertainty. In the most important part of the liquid region, the estimated uncertainty of IAPWS-95 ranges from ±0.001% to ±0.02% in density, ±0.03% to ±0.2% in speed of sound, and ±0.1% in isobaric heat capacity. In the liquid region at ambient pressure, IAPWS-95 is extremely accurate in density (uncertainty ⩽±0.0001%) and in speed of sound (±0.005%). In a large part of the gas region the estimated uncertainty in density ranges from ±0.03% to ±0.05%, in speed of sound it amounts to ±0.15% and in isobaric heat capacity it is ±0.2%. In the critical region, IAPWS-95 represents not only the thermal properties very well but also the caloric properties in a reasonable way. Special interest has been focused on the extrapolation behavior of the new formulation. At least for the basic properties such as pressure and enthalpy, IAPWS-95 can be extrapolated up to extremely high pressures and temperatures. In addition to the IAPWS-95 formulation, independent equations for vapor pressure, the densities, and the most important caloric properties along the vapor–liquid phase boundary, and for the pressure on the melting and sublimation curve, are given. Moreover, a so-called gas equation for densities up to 55 kg m−3 is also included. Tables of the thermodynamic properties calculated from the IAPWS-95 formulation are listed in the Appendix.

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.

The available data on gas-phase basicities and proton affinities of approximately 1700 molecular, radical and atomic neutral species are evaluated and compiled. Tables of the data are sorted (1) according to empirical formula and (2) according to evaluated gas basicity. This publication constitutes an update of a similar evaluation published in 1984.

This compilation contains critically evaluated kinetic data on elementary homogeneous gas phase for use in modelling processes. Data sheets are presented for some 196 Each data sheet sets out relevant data, rate coefficient measurements, an assessment of the reliability of the data, references, and recommended rate parameters. Tables summarizing the preferred rate data are also given. The considered are limited largely to those involved in the of and ethane in air but a few relevant to the chemistry of exhaust gases and to the of aromatic compounds are also included.

Kinetic data for the superoxide radical (HO2⇄O−2 +H+, pK=4.8) in aqueous solution have been critically assessed. Rate constants for reactions of O−2 and HO2 with more than 300 organic and inorganic ions, molecules and other transient species have been tabulated.

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.

This document contains evaluated data on the kinetics and thermodynamic properties of species that are of importance in methane pyrolysis and combustion. Specifically, the substances considered include H, H2, O, O2, OH, HO2, H2O2, H2O, CH4, C2H6, HCHO, CO2, CO, HCO, CH3, C2H5, C2H4, C2H3, C2H2, C2H, CH3CO, CH3O2, CH3O, singlet CH2, and triplet CH2. All possible reactions are considered. In arriving at recommended values, first preference is given to experimental measurements. Where data do not exist, a best possible estimate is given. In making extrapolations, extensive use is made RRKM calculations for the pressure dependence of unimolecular processes and the BEBO method for hydrogen transfer reactions. In the total absence of data, recourse is made to the principle of detailed balancing, thermokinetic estimates, or comparisons with analogous reactions. The temperature range covered is 300–2500 K and the density range 1×1016–1×1021 molecules/cm3. This data base forms a subset of the chemical kinetic data base for all combustion chemistry processes. Additions and revisions will be issued periodically.

Tabulations are presented of the atomic form factor, F (α,Z), and the incoherent scattering function, S (x,Z), for values of x (=sin ϑ/2)/λ) from 0.005 Å−1 to 109 Å−1, for all elements A=1 to 100. These tables are constructed from available state-of-the-art theoretical data, including the Pirenne formulas for Z=1, configuration-into action results by Brown using Brown-Fontana and Weiss correlated wavefunctions for Z=2 to 6 non-relativistic Hartree-Fock results by Cromer for Z=7 to 100 and a relativistic K-shell analytic expression for F (x,Z) by Bethe Levinger for x≳10 Å−1 for all elements Z=2 to 100. These tabulated values are graphically compared with available photon scattering angular distribution measurements. Tables of coherent (Rayleigh) and incoherent (Compton) total scattering cross sections obtained by numerical integration over combinations of F2(x,Z) with the Thomson formula and S (x,Z) with the Klum-Nishina Formual, respectively, are presented for all elements Z=1 to 100, for photon energies 100 eV (λ=124 Å) to 100 MeV (0.000124 Å). The incoherent scattering cross sections also include the radiative and double-Compton corrections as given by Mork. Similar tables are presented for the special cases of terminally-bonded hydrogen and for the H2 molecule, interpolated and extrapolated from values calculated by Stewart et al., and by Bentley and Stewart using Kolos-Roothaan wavefunctions.