摘要:

Thermochemical data on selected gas phase compounds containing sulfur, fluorine, oxygen, and hydrogen are evaluated. These are of particular relevance to plasma chemistry and SF6dielectric breakdown. Values of the enthalpies of formation and the entropy are provided at 298 K. Where no experimental data are available, methods for estimation have been developed for deriving the enthalpy of formation. Data are tabulated for 36 substances.

ISSN:0047-2689    

DOI:10.1063/1.555791

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

This report presents the assessed thermochemical measurements on rubidium compounds upon which the property values, &Dgr;f H0, &Dgr;f G0,S0,C0p, andH0(T)−H0(0) at 298.15 K and &Dgr;f H0(0 K) recommended in the ‘‘NBS Tables of Chemical Thermodynamic Properties’’ are based. Included in this set of thermochemical measurements, or thermochemical reaction catalog, is a comparison of the observed values for the processes in question with those predicted (calculated) from the recommended property values in the forementioned tables. The evaluator’s initially assigned uncertainties on the experimental measurements and final estimated reliabilities on the recommended process values are given. This paper illustrates the evaluation procedure used in preparing the full set of recommended data in the ‘‘NBS Tables of Chemical Thermodynamic Properties’’.

ISSN:0047-2689    

DOI:10.1063/1.555793

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

The standard thermodynamic functions—heat capacity at constant pressureC○p, its ratio to that at constant volume, the entropyS○, the enthalpy minus that at absolute zero (H○−H○0), and the Gibbs energy function (G○−H○0)/Twere calculated for 131 gaseous ions in the temperature interval 100–1000 K, and are presented in tables. The input data included structural information (bond lengths and angles), vibrational spectroscopic information (vibrational frequencies and degeneracies), and electronic level occupation and degeneracies for ions having unpaired electrons. These were taken mainly from a recent review by the authors, and supplemented by further data from the literature, updated to the end of 1985.

ISSN:0047-2689    

DOI:10.1063/1.555792

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

This work reviews and discusses the data on the various thermodynamic properties of manganese and molybdenum available through March 1985. These include heat capacity, enthalpy, enthalpy of transitions and melting, vapor pressure, and enthalpy of vaporization. The existing data have been critically evaluated and analyzed. The recommended values for the heat capacity, enthalpy, entropy, and Gibbs energy function from 0.5 to 2400 K for manganese and from 0.4 to 5000 K for molybdenum have been generated, as have heat capacity values for supercooled &bgr;‐Mn and for &ggr;‐Mn below 298.15 K. The recommended values for vapor pressure cover the temperature range from 298.15 to 2400 K for manganese and from 298.15 to 5000 K for molybdenum. These values are referred to temperatures based on IPTS‐1968. The uncertainties in the recommended values of the heat capacity range from ±3% to ±5% for manganese and from ±1.5% to ±3% for molybdenum.

ISSN:0047-2689    

DOI:10.1063/1.555794

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

This work reviews the data and information available through March 1985 on the various thermodynamic properties of five binary aluminum alloy systems: Al–Fe, Al–Mn, Al–Ni, Al–Si, and Al–Ti. The thermodynamic properties covered in this work are heat capacity, Gibbs energy, enthalpy, and entropy of formation. Existing data have been evaluated and analyzed. The values for heat capacity and room‐temperature enthalpy of formation for a large number of alloys have been generated. For each of the binary alloy systems, the recommended values for integral Gibbs energy, enthalpy, and entropy of formation as well as the partial quantities, activity, and activity coefficients for each component covering the entire composition range have been reported. These values are reported for both solid and liquid alloys.

ISSN:0047-2689    

DOI:10.1063/1.555788

出版商:AIP    

年代:1987

数据来源: AIP

摘要:

Analogous to the importance of13C isotropic shieldings for chemical analysis of liquids with nuclear magnetic resonance spectroscopy,13C chemical shielding anisotropies are proving to be valuable in the characterization of solids. Specifically, molecular geometry is revealed by the full shielding anisotropy and molecular motion may be characterized by changes in the powder pattern. In particular, the principal components of the shielding reveal differences in bonding geometry which may not be correlated to monotonic changes in the isotropic shift. This report is a comprehensive, critical compilation of13C chemical shieldings in solids, organized by carbon functionality. From these data, representative shieldings of common carbon functionalities are calculated.

ISSN:0047-2689    

DOI:10.1063/1.555789

出版商:AIP    

年代:1987

数据来源: AIP

ISSN:0047-2689    

DOI:10.1063/1.555790

出版商:AIP    

年代:1987

数据来源: AIP