Showing papers in "Journal of Physical and Chemical Reference Data in 2001"

Factors Affecting Sorption of Organic Compounds in Natural Sorbent/Water Systems and Sorption Coefficients for Selected Pollutants. A Review

Abstract: Factors affecting sorption of organic pollutants by natural sorbents (soils, sediments, clays, humic materials, and dissolved organic matters) and sorption coefficients for selected pollutants are reviewed on the basis of the literature results and interpretations; with 681 references examined. The most significant aspects of the sorption process are discussed: sorption isotherms and sorption kinetics; effects of sorbent physico-chemical characteristics (pH, cation exchange capacity, ionic strength, surface area, etc.); effect of the temperature; sorption of volatile compounds; effect of the presence of a cosolvent; association with dissolved organic matter; effect of the sorbent concentration; “hysteresis” or nonsingularity in the sorption–desorption process, and its implications in the transport of these contaminants through soil columns. The experimental and prediction methods adopted for the determination and estimation of the sorption coefficients are also described. Literature sorption coefficients ...

Experimental Energy Levels of the Water Molecule

Abstract: Experimentally derived energy levels are presented for 12 248 vibration–rotation states of the H2 16O isotopomer of water, more than doubling the number in previous, disparate, compilations. For each level an error and reference to source data is given. The levels have been checked using energy levels derived from sophisticated variational calculations. These levels span 107 vibrational states including members of all polyads up to and including 8v. Band origins, in some cases estimates, are presented for 101 vibrational modes.

Heat Capacity of Liquids: Critical Review and Recommended Values. Supplement II

Abstract: A study was carried out in which new experimental data on heat capacities of pure liquid organic and some inorganic compounds were compiled, critically evaluated, and recommended values provided. Compounds included in the compilation have a melting point below 573 K. The bulk of the compiled data covers data published in the primary literature between 1993 and 1999 and some data of 2000. However, some data from older sources were also included. The data were taken from almost 1030 literature references. Parameters of correlating equations for temperature dependence of heat capacities of liquids were developed. This paper is an update of a two volume monograph entitled Heat Capacity of Liquids: Critical Review and Recommended Values (96ZAB/RUZ) that was published in 1996 in the Journal of Physical and Chemical Reference Data as Monograph No. 6 and was the product of the IUPAC Project No. 121/11/87.

Equations of State for Cu, Ag, and Au for Wide Ranges in Temperature and Pressure up to 500 GPa and Above

Abstract: New constraints on the volume dependence of the Gruneisen parameter (γ(V)) are derived from a comparison of earlier shock wave data with more recent ultrasonic data for the bulk modulus K0 and its pressure derivative K0′ in the frame of a rigorous Mie–Gruneisen model. This model uses a specially “Modified pseudo-Debye–Einstein model” for an accurate representation of the thermal energy and pressure. Within this framework, previous discrepancies between shock wave and static data concerning the equations of state for various reference materials (like Cu, Ag, and Au) are resolved, the corresponding pressure scale is refined, and the uncertainties in this scale are estimated.

Atomic Weights of the Elements 1999

Abstract: The biennial review of atomic-weight, Ar(E), determinations and other cognate data have resulted in changes for the standard atomic weights of the following elements: fromtonitrogen14.006 74±0.000 07¯14.0067±0.0002¯sulfur32.066±0.00632.065±0.005chlorine35.4527±0.000935.453±0.002germanium72.61±0.0272.64±0.01xenon131.29±0.02131.293±0.006erbium167.26±0.03167.259±0.003uranium238.0289±0.0001238.028 91±0.000 03Presented are updated tables of the standard atomic weights and their uncertainties estimated by combining experimental uncertainties and terrestrial variabilities. In addition, this report again contains an updated table of relative atomic mass values and half-lives of selected radioisotopes. Changes in the evaluated isotopic abundance values from those published in 1997 are so minor that an updated list will not be published for the year 1999. Many elements have a different isotopic composition in some nonterrestrial materials. Some recent data on parent nuclides that might affect isotopic abundances or...

Electron Interactions With c-C 4 F 8

Abstract: Besides its use in plasma etching, perfluorocyclobutane (c-C4F8) has potential applications as a gaseous dielectric, especially in gas mixtures (e. g., see Refs.1-3). Perfluorocyclobutane is also of environmental interest because it is a global warming gas.4 For these reasons, we have recently synthesized and assessed electron collision cross-section and electron transport-coefficient data for this gas.5 The results of this critical assessment are summarized and briefly discussed in this paper.

NIST-JANAF Thermochemical Tables. I. Ten Organic Molecules Related to Atmospheric Chemistry

Abstract: The structural, spectroscopic, and thermodynamic properties of 10 gas phase organic molecules related to atmospheric chemistry, including three peroxides and four carboxylic acids, are reviewed. The calculation of the thermochemical tables involved the critical evaluation of new spectroscopic data, enthalpy of formation determinations, and the use of recent internal rotation data. Since insufficient information to characterize all 10 molecules exists, estimation schemes were used to provide the missing experimental and theoretical data.

Erratum: “Heat Capacity of Liquids. Critical Review and Recommended Values. Volumes I and II.” [J. Phys. Chem. Ref. Data, Monograph No. 6 (1996)]

Abstract: The errata are arranged in the format shown below and are listed as found according to successive pages in the 1996 Monograph No.6. After the page number for specific erratum, there is information provided which indicates the location on the specific erratum on a given page, such as: number and name of table, reference squib, compound name or other pertinent information. If a given error occurs on more than one page, the page numbers are listed for occurrence of each error in a block of consecutive lines. Next, the erratum appears as it is found in the publication; thereafter one finds the correction. The last line offers a comment or explanation about the erratum.

IUPAC-NIST Solubility Data Series. 75. Nonmetals in Liquid Alkali Metals

Abstract: Liquid alkali metals have several physical properties which favor their use in a number of important applications. For example, their large liquidus temperature range and their excellent heat transfer properties are important for use as heat transfer media. They are used in large nuclear reactors in which hundreds of tons of sodium are circulating, and in small parts of engines for cooling of valves. Since these metals are among the most electropositive elements, several of them (Li, Na) can be used in high specific capacity and high energy density batteries at moderately elevated temperatures. The compatibility of metallic constructional materials which are used to contain the liquid metals is strongly influenced by nonmetals present in the liquids. The physical properties of the liquid metals are also influenced by dissolved substances. Several nonmetals dissolved in alkali metals are able to form ternary compounds with components of the constructional materials. Thus, corrosion and compatibility studies have been accompanied by extensive chemical work related to the solutions of non-metallic substances in liquid alkali metals. All available solubility data of nonmetallic elements and some of their compounds in the five liquid alkali metal solvents (Li, Na, K, Rb, and Cs) are collected and compiled. Original publications with reliable data and information on the methods used to generate them are reported in individual Compilations. When numerical data are not given in a publication, the data are often read out from figures and converted into numerical data by the compilers. The precision of this procedure is indicated in the Compilations under Estimated Error. Evaluated solubility data are tabulated at the end of the Critical Evaluations: if there is agreement of at least two independent studies within the experimental error, the solubility values are assigned to the “recommended” category. Values are assigned as “tentative,” if only one reliable result was reported, or if the mean value of two or more reliable studies was outside the error limits. In the tabulation, three, two, or one significant figures are assigned for respective precisions that are better than ±1% and ±10% and worse than ±10%. If necessary, the solubilities are recalculated into mol %. The completeness of this investigation of the literature has been confirmed and extended by studying several reviews dealing with the solution chemistry of substances in the alkali metals. Solubility data are sometimes measured under parameters, which are not standard conditions of such measurements. Frequently measurements are performed under constrained pressure. The solubility of noble gases or other gases, which do not form compounds with the alkali metals, depends on the gas pressures. This dependency is documented in the data sheets. Schematic phase diagrams are presented in systems for which they assist the understanding of the data and the conclusions. They are based on the most recent state of knowledge and generally presented in the Critical Evaluations. Some solubility diagrams are shown in form of a log solubility versus reciprocal temperature function. These figures illustrate the larger scatter of data for systems in which interfering reactions cause unstable behavior of solutions. While several solutes are well defined substances, other systems need still additional studies to define the equilibrium solid state compound. One should realize that estimations of the stoichiometry and thermal stability of ternary compounds are experimentally difficult, and their results are often uncertain.

A Review of Recent Experiments and Calculations Relevant to the Kinetics of the HF Laser

Abstract: A review of rate coefficients relevant to HF laser kinetics modeling is presented. The literature has been surveyed from the last published review in 1983 to the present. Updated HF Einstein emission coefficients are tabulated. Rate coefficients are categorized according to their role in the HF laser model: HF generation, reactive quenching, self-relaxation, V–V energy transfer, vibrational relaxation by atoms and molecules, F2 dissociation, and F atom recombination. In addition, a review of recent experiments and theoretical calculations relevant to the role of rotational nonequilibrium in HF lasers is presented. A list of recommended temperature dependent expressions for critical reaction rate coefficients is given.

IUPAC-NIST Solubility Data Series. 73. Metal and Ammonium Formate Systems

Abstract: This volume reviews the metal and ammonium formate solubility data published up to 1995. So far as the editors are aware, all the solubility data published during this period have been reviewed. Preference has been given to data published in numerical form. Data that appeared only in graphical form may not appear in this volume. In each section the metal atoms are arranged in the order (group) in which they appear in the Periodic Table. Metal formates are crystalline solids having some interesting chemical and physical properties. Several of these salts are important because they have nonlinear optical properties. Specific examples are: LiCHO2⋅H2O (3), NaCHO2 (4), Sr(CHO2)2, and Sr(CHO2)2⋅2H2O, Ba(CHO2)2, formates of Sc, Y and the rare earth elements having the general formula Me(CHO2)3⋅nH2O (where Me=Sc, Y, La, Ce, Pr, Nd, Sm…Lu) and some double salts and mixed salts such as NaCd(CHO2)3, BaCd(CHO2)4⋅2H2O and Li0.9Na0.1CHO2. Some metal formates have useful electric or magnetic characteristics. Thus, Cu(CH...

Thermochemical Properties of Si2F6 and SiF4 in Gas and Condensed Phases

Abstract: The available data for determining the thermochemical parameters for Si2F6 and SiF4 has been assembled. With this information, the thermochemical functions for Si2F6 and SiF4 have been calculated as ideal gases in the harmonic oscillator approximation. These results are presented in the format of the NIST–JANAF Thermochemical Tables, as well as in the format of the CHEMKIN Thermochemical Database. Using the vapor pressure data, the thermochemical parameters for Si2F6 in the solid phase and SiF4 in both the solid and liquid phases have been calculated. These results are compared with available experimental and calculated data. The earlier results are in good agreement with our results. However, the Si2F6 results were not previously available in the JANAF format, and the results for both species are on a much firmer footing with the new experimental data we used. The anharmonicity constants measured earlier for SiF4 permitted a determination of the effect of anharmonicity on the thermochemical properties fo...

Vapor Pressures, Critical Parameters, Boiling Points, and Triple Points of Halomethane Molecular Substances

Abstract: A simple general corresponding-states principle for vapor pressure incorporated with a simple vapor-pressure equation is presented to describe within and extend beyond the range of available experimental data for 25 halomethane substances. Apparatus type, measurement method, and precision and uncertainties are listed for the experimental vapor-pressure data sets. The experimental data with the corresponding ranges have been reviewed to test the present method in representing the vapor-pressure behavior. Comparisons with available data show that the extended corresponding-states principle for vapor pressure has very good accuracies with different data sets. The substance-dependent characteristic parameters such as critical temperature, critical density, critical pressure, and acentric factor are given from reliable literature sources along with the general method. The values of the pressures, along with their first and second derivatives as function of temperature over the entire region from the triple point to the critical point, are tabulated and recommended for scientific and practical uses.

IUPAC-NIST Solubility Data Series. 76. Solubility of Ethyne in Liquids

Abstract: Ethyne was probably first made in the laboratory by Edmund Davy in 1836. It was rediscovered nearly a quarter of a century later by Berthelot who gave it the name acetylene. Since that time ethyne has become a cheap raw material for the synthesis of organic materials and an important industrial fuel. A summary of the available solubility data for ethyne was published by Miller in 1965 [S. A Miller, Acetylene—Its Properties, Manufacture, and Uses (Academic, New York, 1965), Vol. I]. Many more data are now available in a wide range of research papers and patent applications. These data vary in their reliability. In the current work the data for systems included in Miller’s book have been reassessed and complemented by data published more recently. Literature has been surveyed to 1999. Data for a system may be unreliable unless two or more groups of workers have published values in close agreement. Where possible values of the mole fraction solubility at a partial pressure of 101.3 kPa have been tabulated. Equations have been given for the variation of mole fraction with temperature in cases in which values over a temperature range are available. The greater the number of independent sources of the data the more the reliance which can be placed on the utility of the resulting equation. Extrapolation of such equations beyond the temperature range of experimental measurements can lead to errors. In many of the systems it may be assumed that approximate values of the mole fraction solubility,x1, at a partial pressure of 101.3 kPa may be obtained by linear extrapolation of values for lower partial pressures,p1, on the assumption that x1/p1 is approximately constant. However a similar linear extrapolation of solubilities at pressures appreciably higher that 101.3 kPa to give mole fraction solubilities at 101.3 kPa can lead to gross errors. For the purpose of evaluation of data use has been made of the Krichevsky–Il’inskaya equation to obtain approximate values of solubilities at 101.3 kPa from measurements at higher pressures. These values were then compared with measurements made at or near to 101.3 kPa.

IUPAC-NIST Solubility Data Series. 74. Actinide Carbon Compounds

Abstract: This volume presents solubility data of the carbonates, salts of carboxylic acids, and other carbon containing compounds of actinides. Covered are compounds of thorium, uranium, neptunium, plutonium, americium, and one system for curium. No solubility data on carbonates or other carbon containing compounds have been found for other actinide elements. The literature has been covered up to the end of 1999, and there was a great effort to have the literature survey as complete as possible. Only those published results that report meaningful data were considered for the volume. Papers that reported qualitative results with statements like “sparingly soluble” or “insoluble,” etc. were not considered. In addition to papers that published numerical data, some papers that presented data in graphical form only were considered as well. They were considered for the volume either if no other data were available for the system, if the data were published in difficult to obtain older literature, or if the data were considered to be of importance for other reasons. For many compounds it was not possible to provide the Chemical Abstracts Registry Numbers since these have not yet been assigned. For this reason, the Registry Number index is incomplete.