Vapor Pressure of Antimony by the Torsion‐Effusion Method

The phase relations for the systems Pt/As, Os/As, Os/Se, and Ru/Se have been examined in the range 850–1 250 °K. Using the torsion effusion method, the decomposition pressures of PtAs2, OsAs2, OsSe2, and RuSe2 have been measured as a function of temperature. The apparatus and procedures were verified by measuring the vapor pressure of liquid silver. Equilibrium pressures were obtained for PtAs2 and RuSe2. OsAs2 exhibited an orifice area dependent nonequilibrium behavior and OsSe2 exhibited a time dependent nonequilibrium behavior. Equilibrium pressures were estimated in these latter two cases. Total equilibrium decomposition pressures (Pt), i.e. the pressure of arsenic or selenium vapors in equilibrium with each phase, are best described by the equations: [Formula: see text]Literature data on the equilibria between the various molecular species in selenium and arsenic vapor indicate that at these pressures and temperatures the vapor in equilibrium with the selenides is essentially pure Se2, but the vapor over the arsenides is a mixture of As2 and As4.The heats and entropies of decomposition of PtAs2, OsAs2, OsSe2, and RuSe2 have been calculated from the decomposition pressure data. The standard heats of formation at 298 °K are −42.0 ± 3.5, −18.5 ± 2.0, −32.5 ± 5.0, and −42.9 ± 3.5 kcal/mole, respectively. Heats of formation of MnSe2, CoSe2, NiSe2, and RhSe2 have been estimated using the heats of formation of OsSe2 and RuSe2, the Born–Mayer equation, and the Born–Haber cycle. These are −96 ± 8, −70 ± 8, −41 ± 8, and −12 ± 12 kcal/mole, respectively.

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Use of the torsion-effusion method for adsorption measurements

Bulletin of the Academy of Sciences of the USSR Division of Chemical Science ◽

10.1007/bf00854386 ◽

1971 ◽

Vol 20 (9) ◽

pp. 1769-1773

Author(s):

K. O. Murdmaa ◽

V. V. Serpinskii

Keyword(s):

Effusion Method ◽

Torsion Effusion

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High‐temperature thermodynamic properties of MnS by the dynamic Knudsen–torsion effusion method

The Journal of Chemical Physics ◽

10.1063/1.430308 ◽

1975 ◽

Vol 62 (10) ◽

pp. 3875-3882 ◽

Cited By ~ 16

Author(s):

Puligandla Viswanadham ◽

Jimmie G. Edwards

Keyword(s):

High Temperature ◽

Thermodynamic Properties ◽

Effusion Method ◽

Torsion Effusion

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A VAPOR PRESSURE STUDY OF THE ALLOYS OF MANGANESE WITH COPPER

Canadian Journal of Chemistry ◽

10.1139/v63-379 ◽

1963 ◽

Vol 41 (10) ◽

pp. 2591-2599 ◽

Cited By ~ 11

Author(s):

B. F. Peters ◽

D. R. Wiles

Keyword(s):

Vapor Pressure ◽

Physical Properties ◽

High Temperatures ◽

Vapor Pressures ◽

Knudsen Effusion ◽

Sources Of Error ◽

Manganese Alloys ◽

Copper Manganese ◽

Knudsen Effusion Method ◽

Effusion Method

The Knudsen effusion method has been applied in a study of the vapor pressures of manganese in equilibrium with copper–manganese alloys at high temperatures. The amount of manganese effused was determined by the use of radioactive Mn54. The odd behavior noted in this system at 20–30% Mn, observed in a number of studies of various physical properties, has been observed once more in the apparent activity of manganese. Some discussion is given of the Knudsen effusion method, particularly regarding some possible sources of error.

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Vaporization and Sublimation Enthalpies of Six Carbone-12 Peroxide Containing Derivatives

Chemistry & Chemical Technology ◽

10.23939/chcht04.02.085 ◽

2010 ◽

Vol 4 (2) ◽

pp. 85-89

Author(s):

Volodymyr Dibrivnyi ◽

◽

Natalya Boutylina ◽

Galyna Melnyk ◽

Yurij Raevskyi ◽

...

Keyword(s):

Hydrogen Atom ◽

Vapor Pressure ◽

Saturated Vapor Pressure ◽

Saturated Vapor ◽

Knudsen Effusion ◽

Dsc Method ◽

Knudsen Effusion Method ◽

Derivatives Of ◽

Effusion Method

Vaporization and sublimation enthalpies of six peroxide containing derivatives of carboranes were obtained on the basis of temperature dependencies of the saturated vapor pressure that was measured by Knudsen effusion method. Fusion enthalpies were defined by DSC method. The inputs of carborane nuclei and the increments of the hydrogen atom deputies groups in carboranes were determined.

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