Volume 9, Issue 4, October 1980
Index of content:
Molten Salts Data as Reference Standards for Density, Surface Tension, Viscosity, and Electrical Conductance: KNO3 and NaCl9(1980); http://dx.doi.org/10.1063/1.555634View Description Hide Description
Accuracy estimates for physical propertymeasurements are usually based on somewhat subjective quality judgements and the difficulties encountered in interpreting accuracy statements in the literature are frequently compounded through lack of details on the methods of measurements, chemical purity, and related experimental aspects. In the present communication we report the results of a Standards Program initiated in 1973 with participating laboratories in Czechosloskia, German Democratic Republic‐DDR, Japan, Norway, Poland, Rumania, and U.S.A. Potassium nitrate (m.335 °C) and sodium chloride (m 800 °C) were selected as the two reference salts for the properties: density, surface tension,viscosity, and electrical conductance. The results of the measurements have been critically examined, and are reported herewith. It has been possible to resolve some of the difficulties encountered in accuracy estimates through this ’’round‐robin’’ series of measurements, and to up‐grade some of the data‐sets to calibration‐quality reference standards.
Molten Salts: Vol. 5, Part 1, Additional Single and Multi‐Component Salt Systems. Electrical Conductance, Density, Viscosity, and Surface Tension Data9(1980); http://dx.doi.org/10.1063/1.555635View Description Hide Description
Data on the electrical conductance, density, and surface tension of more than ninety additional multi‐component salt systems have been systematically collected and evaluated. Results are given for mixtures over a range of compositions and temperatures. Values of the above properties for some sixty single salt systems are also reported.
Pair, Triplet, and Total Atomic Cross Sections (and Mass Attenuation Coefficients) for 1 MeV‐100 GeV Photons in Elements Z=1 to 1009(1980); http://dx.doi.org/10.1063/1.555629View Description Hide Description
Tables of photon cross sections and mass attenuation coefficients for all elements Z=1 to 100 are given for photo energies in the range 1 MeV to 100 GeV. The pair and triplet production cross sections take into account recent theoretical work, including atomic form factor and incoherent scattering function data, as well as extensive new total attenuation coefficient measurements at Mainz. Cross section values for the atomic photoeffect and coherent and incoherent (Compton) scattering are explicitly listed and are included in the total cross sections (excluding photonuclear) and mass attenuation coefficients.
9(1980); http://dx.doi.org/10.1063/1.555630View Description Hide Description
Fundamental vibrational frequencies of 94 molecular forms of 23 polyatomic chain molecules of halogenoalkanes and halogenoalkyl ethers consisting of the CH3, CH2, O, F, Cl, Br, and I groups are given as an extension of tables of molecular vibrational frequencies published in the NSRDS‐NBS publication series and in this journal. On preparing the tables in this part, an approach, similar to that in Part 9 but different from that in earlier parts, based on the calculations of normal vibration frequencies was adopted. A set of force constants which explains all the frequencies of small molecules for which the assignments had been established was obtained and then the frequencies of larger molecules were calculated and compared with the frequencies observed in the infrared and Raman spectra. The tables provide a convenient source of information for those who require vibrational energy levels and related properties in molecular spectroscopy,thermodynamics,analytical chemistry, and other fields of physics and chemistry.
9(1980); http://dx.doi.org/10.1063/1.555631View Description Hide Description
Experimental evidence for steam and other fluids has demonstrated the existence of an anomalous enhancement of the dynamic viscosity in the close vicinity of the critical point. A re‐analysis of the experimental evidence for the viscosity of steam indicates that the observed behavior of the critical viscosity enhancement is consistent with current theoretical predictions. An interpolating equation for the dynamic viscosity of water substance is presented which is in good agreement with the experimental viscosity data in a large range of temperatures and pressures. The equation contains a smaller number of coefficients than the current international equation for the viscosity of water substance and incorporates the enhancement of the viscosity in the close vicinity of the critical point.
9(1980); http://dx.doi.org/10.1063/1.555632View Description Hide Description
This paper reviews and evaluates the experimental works of the static dielectric constant(permittivity) of water and steam over the century. The critically evaluated experimental data are represented by a function of temperature and density. This representation was carefully examined in the light of the criteria for smoothness and physical plausibility. As a result of this work, which was largely stimulated by the activities of the International Association for the Properties of Steam, a new International formulation for the static dielectric constant of water and steam was adopted. This formulation covers a temperature range from 0 to 550 °C and a pressure range up to 500 MPa.
9(1980); http://dx.doi.org/10.1063/1.555633View Description Hide Description
The more than one dozen papers dealing with the solubility of mercury (1) chloride in water or in aqueous chloride solutions have been compiled in the format set by the IUPAC Solubility Data Project, and have been evaluated. Mercury (I) chloride dissolves in water, forming the following species: He(OH)2, HgCl2, HgOH+, HgOH+, HgCl+, Hg2+ 2, and Hg2OH− in addition to H+ and Cl−. In excess chloride solutions it dissolves to give, mainly, HgCl− 3 and HgCl2− 4. Thus, many homogeneous equilibria have to be considered beside the two heterogeneous ones; Hg2Cl2(s)=Hg2+ 2(aq)+2Cl−(aq) and Hg2+ 2(aq)=Hg2+(aq)+ Hg(l), of which K ° s0 and (K ° r)−1, respectively, are the equilibrium constants. The papers in which the total solubility (sum of all the mercury containing aqueous species) and the solubility product (derived from e.m.f. data) are reported do not give as accurate and reliable quantities as are obtained from the appropriate standard electrode potentials. The following values are recommended as valid at 298.15 K: log (K ° s0/mol2kg−2=−17.844±0.017, d log (K ° s0/mol2kg−2)/d T?0.0002)−(6.0±0.4)×10 −1 (T/K−2.98.15), ΔG ° s0=101.86±0.10 kJ mol−1, ΔS ° s0=−12.7±0.9 JK−1 mol −1. ΔH ° s0 =98.08±0.18 kJ mol−1, ΔC ° p,s0=−0.36±0.04 JK−1 mol−1 (this item, tentatively), and c Hg?1.6)×10−6 mol dm−3 (the total aqueous solubility).