Showing papers in "Journal of Physical and Chemical Reference Data in 2023"
TL;DR: In this article , the authors present the state of knowledge of the thermophysical properties of water in all its phases and the reference formulations that provide standardized, recommended values of these properties for science and industry.
Abstract: This Review presents the state of knowledge of the thermophysical properties of water in all its phases and the reference formulations that provide standardized, recommended values of these properties for science and industry. The main focus is the standard formulations adopted by the International Association for the Properties of Water and Steam (IAPWS), but some properties are covered for which IAPWS has not yet adopted recommendations. It is emphasized that, despite many advances over the last 100 years, there is room for further improvement, and current weaknesses and opportunities for advancing knowledge are discussed. Particular attention is given to the formulation for thermodynamic properties of fluid water known as IAPWS-95, which is planned to be replaced in the coming years. Additional topics include properties of heavy water and seawater and the growing ability of molecular modeling to provide properties at conditions where experimental measurements are difficult or inaccurate.
4 citations
TL;DR: In this paper , the spectrum properties of saturated carbocyclic hydrocarbons with a single ring with three or more members are discussed and the dissociation directions of these compounds and diagnostically important ions are identified.
Abstract: Electron ionization (EI) mass spectra of saturated carbocyclic hydrocarbons containing a single ring with three or more members are discussed followed by the examination of their unsaturated analogs, including aromatic hydrocarbons. Mass spectrometry characteristics of heterocyclic compounds for each cycle size with one, two, three, and more hetero-atoms in a ring are considered along with their mono- and polyunsaturated analogs. An effect of the (a) size of a cycle; (b) number, nature, and location of elements in a ring; (c) position and nature of ring substituents; and (d) nature and location of unsaturation on the dissociation is revealed. Characteristic dissociation directions of these compounds and diagnostically important ions in their spectra are identified. Basic dissociation rules for alicyclic, heterocyclic, and aromatic compounds under EI are established for further use in the analysis of complex chemicals containing these structural elements.
1 citations
TL;DR: In this paper , surface tension values for 82 ethers have been compiled from databases, books, and papers in the literature, and recommended correlations are proposed for 81 ethers, including common substances, alcohols, refrigerants, organic acids, n-alkanes, and esters.
Abstract: Surface tension values for 82 ethers have been compiled from databases, books, and papers in the literature. The data were carefully screened, and finally, 2122 values were selected. Each fluid dataset has been fitted with the Guggenheim–Katayama correlation with two, four, or six adjustable parameters, except diphenyl ether, for which the data taken from different sources clearly disagree. Thus, recommended correlations are proposed for 81 ethers. The proposed correlations provide mean absolute deviations equal to or below 0.5 mN/m and mean absolute percentage deviations below 2.6% for 79 ethers. Moreover, percentage deviations below 9.5% are obtained for all the selected data of 78 ethers. The highest deviations found are due to the disagreement between the data obtained from different sources and not to an inadequate mathematical form of the correlation model. These correlations are added to the collection of those previously proposed for different fluids, including common substances, alcohols, refrigerants, organic acids, n-alkanes, and esters.
1 citations
TL;DR: In this paper , thermodynamic models based on the corresponding states framework with departure terms are developed for the refrigerant pairs R-32/1234yf, R-1234ze(E), R-16/227ea, R1234 yf/152a, and R-125/12 34yf.
Abstract: In this work, thermodynamic models based on the corresponding states framework with departure terms are developed for the refrigerant pairs R-32/1234yf, R-32/1234ze(E), R-1234ze(E)/227ea, R-1234yf/152a, and R-125/1234yf. These models are based on new measurements of density, speed of sound, and phase equilibria, combined with the data available in the literature. The model for R-32/1234yf is most comprehensive in its data coverage, with speed of sound deviations within 1%, density deviations within 0.1%, and bubble- and dew-point pressure deviations within 1%. The other mixtures have generally more limited data availability but a similar goodness of fit.
1 citations
TL;DR: In this article , the first and second moments of the first eight excited electronic states were determined in terms of the total internal partition sum and the translational partition sum for 14N2, 14N15N, and 15N2.
Abstract: The total partition sum, Q(T), and its first and second moments, Q′(T) and Q″(T), were determined in terms of the total internal partition sum, Qint(T), and the translational partition sum, Qtrans(T), for 14N2, 14N15N, and 15N2. The total internal partition sum was computed using term values determined using the molecular constants of Le Roy et al. [J. Chem. Phys. 125, 164310 (2006)] for the ground electronic state and molecular constants for the first eight excited electronic states. The work of Le Roy et al. provides the best term values available and, hence, the most accurate total internal partition sums and their first and second moments. The convergence of Qint(T) and its moments were carefully studied and resulted in values with small uncertainty to 9000 K. From these quantities, the isobaric heat capacity, the Helmholtz energy, the entropy, the enthalpy, the Gibbs function, and the JANAF functions S0, hef, and gef, were computed on a 1 K grid from 1 to 9000 K. The resulting thermodynamic quantities are the most accurately determined from the direct summation of Q(T), Q′(T) and Q″(T). These data are compared with literature values.
TL;DR: The literature has been surveyed up to the end of 2021 as mentioned in this paper , and the recommended values of the cross-sections are presented for each of these processes, the recommended value of cross sections are presented.
Abstract: Electron collision cross section data are complied from the literature for electron collisions with the nitrogen molecules, N2, N2+, and N2*. Cross sections are collected and reviewed for total scattering, elastic scattering, momentum transfer, rotational excitation, vibrational excitation, electronic excitation, dissociative processes, and ionization. The literature has been surveyed up to the end of 2021. For each of these processes, the recommended values of the cross sections are presented.
TL;DR: In this paper , a new equation of state explicit in the Helmholtz energy with independent variables of temperature and density was developed, which includes a new associating term, and its uncertainties in density, vapor pressure, saturated liquid and vapor densities, and caloric properties were estimated by comparisons with experimental data.
Abstract: Fluid ammonia is highly associated because of strong intermolecular hydrogen bonding. This causes different behavior of thermophysical properties from nonpolar fluids, as reflected, for example, in the heat capacity. In this work, a new equation of state explicit in the Helmholtz energy with independent variables of temperature and density was developed, which includes a new associating term. Its uncertainties in density, vapor pressure, saturated liquid and vapor densities, and caloric properties were estimated by comparisons with experimental data. The new equation of state is valid from the triple-point temperature (195.49 K) to 725 K at pressures up to 1000 MPa and densities up to 53.13 mol dm−3. Physically correct behavior within the region of validity and at extremely high temperatures and pressures, and at temperatures far below the triple-point temperature, was obtained by applying constraints on various properties. The unique physical behavior of ammonia shown in some thermodynamic properties is described in detail, which will provide a preliminary template for developing equations of state for other associating fluids.
TL;DR: In particular, integral cross sections for elastic scattering, summed discrete electronic-state excitation, and ionization scattering processes are reported over an extended incident electron-energy range as mentioned in this paper .
Abstract: Results from the application of optical potential, relativistic optical potential, relativistic convergent close-coupling, and binary encounter Bethe models to electron scattering from gas-phase cadmium are presented. In particular, integral cross sections for elastic scattering, summed discrete electronic-state excitation, and ionization scattering processes are reported over an extended incident electron-energy range. Total cross sections are constructed by taking their sum. Measurements are presented for elastic scattering and for excitation to the 51P1 state. The theoretical and experimental results are compared to previous calculations and measurements. Recommended electron cross-section datasets are constructed over an incident electron energy range of 0.01–10 000 eV.
TL;DR: In this article , an analysis of experimental measurements of the properties of chlorine dioxide gives ΔfG°(OClO·, g) = 116.3 ± 2.0, ΔfH°(ClO2−, aq) = 26.9 ± 1.5 kJ mol−1, and ΔsolS = −96.1 ± 4.0 kJ
Abstract: An analysis of experimental measurements of the properties of chlorine dioxide gives ΔfG°(OClO·, g) = 116.3 ± 2.0, ΔfH°(OClO·, g) = 98.5 ± 2.0 kJ mol−1, ΔfG°(ClOO·, g) = 112.5 ± 1.5, and ΔfH°(ClOO·, g) = 98.3 ± 1.5 kJ mol−1. An analysis of OClO· solubility measurements gives Ksol = 1.01 ± 0.15 mol l−1 atm−1, ΔsolH = −28.9 ± 1.5 kJ mol−1, and ΔsolS = −96.9 ± 4 J mol−1 K−1. The uncertainties provided in this paper are expanded uncertainties U or 2 σ (95% confidence internal). These results and the redox potential E°(OClO·, aq/ClO2−, aq) = 0.935 ± 0.02 V give ΔfG°(ClO2−, aq) = 26.1 ± 4.0 kJ mol−1, value significantly larger than the value in the NBS Tables of Chemical Thermodynamic Properties.
TL;DR: In this paper , a line position and line intensity analysis for the H218O isotopic species of the water molecule is carried out for the lowest lying vibrational states of the molecule.
Abstract: Line position and line intensity analyses are carried out for the H218O isotopic species of the water molecule. Both datasets involve the five lowest lying vibrational states. For the line position analysis, the dataset includes infrared and far infrared transitions recorded in this work using high-temperature Fourier transform emission spectroscopy. Also included are already published infrared, far infrared, microwave, terahertz, Doppler-free combination differences, and kHz accuracy lines. The fitting is carried out with the bending–rotation approach and allows us to reproduce 12 858 line positions involving levels with J ≤ 20 and Ka ≤ 18, with a unitless standard deviation of 1.9, varying 207 spectroscopic parameters. For the line intensity analysis, far infrared line intensities measured in this work using Fourier transform spectroscopy in addition to previously measured line intensities are fitted. 5612 line intensities are accounted for with a unitless standard deviation of 1.5. The results from both analyses are used to build a line list for atmospherical purposes, spanning the 2–5000 cm−1 spectral range and containing 7593 lines. This line list and calculated energies and line intensities are compared to those already published.
TL;DR: In this article , a critical assessment of the limiting electrical conductivity data (Λ°) for aqueous HCl, KOH, and NaOH measured above room temperature is presented.
Abstract: High-temperature tracer diffusion coefficients for H3O+ and OH− are important parameters in the modeling of diffusion-controlled reaction kinetics and mass transport processes under hydrothermal conditions, and these tracer diffusion coefficients are directly related to the ionic electrical conductivities in the limit of infinite dilution through the Nernst–Einstein relationship. The limiting conductivity of H3O+ and OH− in water is controlled by two separate mechanisms of ionic movement: (i) the bulk ionic diffusion and (ii) proton hopping, also known as “Grotthuss” mechanism and/or “prototropic transfer.” This work reports a critical assessment of the limiting electrical conductivity data (Λ°) for aqueous HCl, KOH, and NaOH measured above room temperature. The initial assessed dataset included temperatures from 273.15 K up to 873.15 K and water densities from 1000 kg m−3 down to 270 kg m−3 and was reduced down to a final critically evaluated dataset spanning temperatures between 273.15 and 678.15 K and densities between 346 and 1006 kg m−3. The results were used to derive values for the excess conductivity due to prototropic transfer, λE°, of H3O+ and OH− using correlations previously reported for aqueous KCl. Simple empirical correlations of water viscosity and density were derived for Λ°(HCl), Λ°(KOH), Λ°(NaOH), λE°(H3O+), and λE°(OH−). Tests using the λE°(OH−) correlation and a previously reported function for Λ°(NaCl) show that the NaOH data can be accurately reproduced to within the estimated uncertainties. The reported correlations provide a means to model more accurately the tracer diffusion coefficients for H3O+ and OH− to supercritical conditions.
TL;DR: In this article , the Boltzmann constant kB and the differences T − T90 that used cylindrical acoustic gas thermometry (c-AGT) were discussed.
Abstract: We review recent determinations of the Boltzmann constant kB and the differences T − T90 that used cylindrical acoustic gas thermometry (c-AGT). These determinations measured the acoustic resonance frequencies of argon gas enclosed by metal-walled, cylindrical cavities. (Here, T is the thermodynamic temperature and T90 is the temperature measured on the International Temperature Scale of 1990, ITS-90.) In the range 234–303 K, the standard uncertainty of c-AGT ranges from 1.9 × 10−6T to 2.6 × 10−6T. This uncertainty is much smaller than the errors in ITS-90; therefore, c-AGT can help improve ITS-90. Moreover, we are extending c-AGT up to 1358 K. With increasing temperatures, c-AGT becomes advantageous relative to AGT based on quasi-spherical cavities because long cylindrical cavities (1) naturally fit into cylindrical heat pipes or multi-shelled thermostats; (2) provide the immersion required by transfer temperature standards, such as long-stemmed platinum resistance thermometers; and (3) have more useful, low-frequency acoustic resonances. In preparation for high-temperature c-AGT, we identified suitable materials for fabricating cylindrical cavities and we developed techniques for measuring acoustic resonance frequencies using sources and detectors outside the high-temperature thermostat. We also considered alternative test gases and optimal dimensions of cavities.