Enthalpies dicarbides

Carbides.— The crystal chemistry of ternary and more complex carbides has been reviewed. The dissociation energies of gaseous metal dicarbides have also been reviewed and compared with those of the corresponding chal-cogenide systems for which information is available. The results of two mass-spectrometric investigations of the atomization energies ( atom,o) dissociation energies (Z)S), and enthalpies of formation (A/ff°... 

The vaporization studies of the solid rare earth carbides by using the mass spectrometry Knudsen effusion method have succeeded in determining the standard enthalpy of formation, A//° 29S> for some of the solid rare earth dicarbides through the reaction... 

Many of the thermodynamic data presented in the following tables have been re-evaluated. The enthalpies of formation of carbon vapors are those given in JANAF tables (Stull and Prophet 1971). For example, AHIj(C, g) = 709.5 1.9kJ/mol has been used in these reevaluations. The table 10 presents the enthalpies of formation and the enthalpies of atomization for the rare-earth dicarbide vapors. The listed uncertainties are the best estimates taking into account the inaccuracies in the experimentally measured quantities such as the temperature, ion currents, pressure calibrations, etc., of the mass spectrometric data, and also due to the estimated values of the Gibbs energy functions. All the... 

The enthalpies of formation and the enthalpies of atomization of rare-earth dicarbide... 

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