Vaporization Of Compound And Alloys At High Temperature Part I. Mass Spectrometric Determination of the Dissociation Energies of the Molecules AgAu, AgCu, AuCu
Report Number: WADD TR 60-782 Part I
Author(s): Ackerman, Marcel, Drowart, J., Stafford, Fred E.
Corporate Author(s): University of Brussels
Laboratory: Materials Central
Date of Publication: 1960-11
Pages: 30
Contract: AF 61(052)-225
DoD Project: 7350
DoD Task: 73500
Identifier: AD0297959
Abstract:
The vapors issuing from mullite and Graphite Knudsen cells containing pure metals and alloys of the triad Cu-Ag-Au have been analyzed mass spectrometrically. From the experimental ratios of diatomic to monoatomic species and the vapor prssures of the elements, the following dissociation energies are obtained: D°0(Cu2) = 43.2 ± 2.2 kcal D°0 (AgAu) = 47.6 ± 2.2 D°0(Ag2) = 35.7 ± 2.2 kcal D°0 (AgCu) = 40.6 ± 2.2 D°0(Au2) = 51.9 ± 2.2 kcal D°0 (AgCu) = 54.3 ± 2.2 These are based on Hvap298 = 81.1, 68.4 and 87.5 cal/mole for Cu, Ag and Au where D0 of AgAu depends on the value for Cu, and D°0 of AgAu and AuCu on Au. The uncertainties quote do not include the uncertainty in ΔHvap. These result are interpreted in terms of chemical bonding theories. The relation between bonding in the gas and in the pure condensed phases is again observed. Furthermore, a previously unobserved qualitative relation between the dissociation energy of the asymmetrical molecule and the heat of formation of the corresponding alloys is indicated
Provenance: IIT
Author(s): Ackerman, Marcel, Drowart, J., Stafford, Fred E.
Corporate Author(s): University of Brussels
Laboratory: Materials Central
Date of Publication: 1960-11
Pages: 30
Contract: AF 61(052)-225
DoD Project: 7350
DoD Task: 73500
Identifier: AD0297959
Abstract:
The vapors issuing from mullite and Graphite Knudsen cells containing pure metals and alloys of the triad Cu-Ag-Au have been analyzed mass spectrometrically. From the experimental ratios of diatomic to monoatomic species and the vapor prssures of the elements, the following dissociation energies are obtained: D°0(Cu2) = 43.2 ± 2.2 kcal D°0 (AgAu) = 47.6 ± 2.2 D°0(Ag2) = 35.7 ± 2.2 kcal D°0 (AgCu) = 40.6 ± 2.2 D°0(Au2) = 51.9 ± 2.2 kcal D°0 (AgCu) = 54.3 ± 2.2 These are based on Hvap298 = 81.1, 68.4 and 87.5 cal/mole for Cu, Ag and Au where D0 of AgAu depends on the value for Cu, and D°0 of AgAu and AuCu on Au. The uncertainties quote do not include the uncertainty in ΔHvap. These result are interpreted in terms of chemical bonding theories. The relation between bonding in the gas and in the pure condensed phases is again observed. Furthermore, a previously unobserved qualitative relation between the dissociation energy of the asymmetrical molecule and the heat of formation of the corresponding alloys is indicated
Provenance: IIT