Vapor Pressure of Antimony by the Torsion-Effusion Method

Journal Article · Sun Jan 01 04:00:00 EST 1961 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.1701217· OSTI ID:4840542

Rosenblatt, Gerd M.; Birchenall, C. Ernest

The pressures and mean molecular weights of the vapors over solid antimony (420-550 deg C) and solid zinc (250-335 deg C) were determined by simultaneous measurements by the torsion-momentum and Knudsen weight loss methods. The torsion measurement was calibrated with mercury at 20 deg using a mercury vapor pressure of 2.96 x 10^-3 mm Hg determined by concurrent weight loss experiments. Zinc vapor is confirmed to be monatomic. The zinc pressure data are represented by logP_mm = (8.741 plus or minus 0.218) -- (6630 ± 125)/T giving DELTA H₂₉₈ i deg (vap) = 30.73 plus or minus 0.57 and 31.18 plus or minus 0.12 kcal/mole by the second law and third law of thermodynics, respectively, in excellent agreement with previously reported results. The vapor over solid antimony is all Sb₄ molecules within experimental error. Least-squares analysis of the antimony data yields logP_mm = (10.571 ± 0.090) -- (10 300 ± 68)/T, pressures 10-40% lower than those previously reported. The heat of vaporization of Sb ₄(g) at 298.16 deg K is 49.83 plus or minus 0.31 kcal/mole by the second law and 49.45 plus or minus 0.09 by the third law of thermodynamics.

• Research Organization: Princeton Univ., N.J.
• Sponsoring Organization: USDOE
• NSA Number: NSA-15-030654
• OSTI ID: 4840542
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 3 Vol. 35; ISSN JCPSA6; ISSN 0021-9606
• Publisher: American Institute of Physics (AIP)
• Country of Publication: Country unknown/Code not available
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ANTIMONY
EVAPORATION
HEATING
MEASURED VALUES
MERCURY
MOLECULES
PRESSURE
SOLIDS
TEMPERATURE
THERMODYNAMICS
VAPORS
WEIGHT
ZINC