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Paolo Scardala - One of the best experts on this subject based on the ideXlab platform.
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Vapor Pressure of Zirconium Tetrafluoride
Journal of Chemical & Engineering Data, 2011Co-Authors: Bruno Brunetti, Vincenzo Piacente, Paolo ScardalaAbstract:Measurements were made of the vapor pressures of zirconium tetrafluoride by using a torsion effusion apparatus. The temperature dependence fit the Equation: Log(p/Pa) = (15.20 ± 0.15) − (11 900 ± 200)/(T/K) (from 685 to 828 K). The compound vaporizes congruently in the monomeric form. With treatment of the measured vapor pressures by second- and third-law methods, the standard sublimation enthalpy ΔsubH°(298 K) = (239 ± 2) kJ·mol−1 was obtained.
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Some Thermodynamic Properties of C76 and C84
The Journal of Physical Chemistry B, 1997Co-Authors: Bruno Brunetti, Guido Gigli, Edoardo Giglio, Vincenzo Piacente, Paolo ScardalaAbstract:The vapor pressures of C76 were measured over the temperature range 834−1069 K by the torsion−effusion method. The results are well represented by the following linear Equation: Log(p/kPa) = (8.23...
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Study on sulfur vaporization from covellite (CuS) and anilite (Cu1.75S)
Journal of Alloys and Compounds, 1994Co-Authors: Bruno Brunetti, Vincenzo Piacente, Paolo ScardalaAbstract:Abstract Covellite decomposes according to the reaction: 4.667CuS → 2.667Cu1.75S(S) + S2(g). The sulfur vapour pressures measured in the temperature range 551.5–627 K by the torsion-effusion method are represented by the Equation: Log p (kPa) = (11.30 ± 0.30) − (8290 ± 100)/T. At high temperature, the anilite vaporizes incongruently according to the Equation: 16Cu1.75S(s) → 14Cu2S(s) + S2(g), and the sulfur pressures are well represented in the temperature range 770.5–877 K by the Equation: Log p (kPa) = (10.49 ± 0.40) − (11470 ± 300)/T. The enthalpies associated with these reactions are, ΔH°298 = 178 ± 4 kJ mol−1 and 268 ± 7 kJ mol−1 for reactions 1 and 2 respectively, obtained from second- and third-law treatment of the data. From these reactions, the heat of formation of Cu1.75S, ΔformH°298 = −74 kJ mol−1, was derived.
Bruno Brunetti - One of the best experts on this subject based on the ideXlab platform.
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Vapor Pressure of Zirconium Tetrafluoride
Journal of Chemical & Engineering Data, 2011Co-Authors: Bruno Brunetti, Vincenzo Piacente, Paolo ScardalaAbstract:Measurements were made of the vapor pressures of zirconium tetrafluoride by using a torsion effusion apparatus. The temperature dependence fit the Equation: Log(p/Pa) = (15.20 ± 0.15) − (11 900 ± 200)/(T/K) (from 685 to 828 K). The compound vaporizes congruently in the monomeric form. With treatment of the measured vapor pressures by second- and third-law methods, the standard sublimation enthalpy ΔsubH°(298 K) = (239 ± 2) kJ·mol−1 was obtained.
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Absolute Total Vapor Pressure of Gallium Dichloride
Journal of Chemical & Engineering Data, 2010Co-Authors: Bruno BrunettiAbstract:The total vapor pressure of gallium dichloride was determined by the torsion method over the temperature range of (372 to 441) K, and its temperature dependence was represented by the Equation Log(p/Pa) = (14.23 ± 0.30) − (5829 ± 100)/(T/K). From this Equation the second-law sublimation enthalpy of a mole of gaseous mixture was derived as ΔsubH°(406 K) = (111 ± 2) kJ·mol−1.
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Some Thermodynamic Properties of C76 and C84
The Journal of Physical Chemistry B, 1997Co-Authors: Bruno Brunetti, Guido Gigli, Edoardo Giglio, Vincenzo Piacente, Paolo ScardalaAbstract:The vapor pressures of C76 were measured over the temperature range 834−1069 K by the torsion−effusion method. The results are well represented by the following linear Equation: Log(p/kPa) = (8.23...
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Study on sulfur vaporization from covellite (CuS) and anilite (Cu1.75S)
Journal of Alloys and Compounds, 1994Co-Authors: Bruno Brunetti, Vincenzo Piacente, Paolo ScardalaAbstract:Abstract Covellite decomposes according to the reaction: 4.667CuS → 2.667Cu1.75S(S) + S2(g). The sulfur vapour pressures measured in the temperature range 551.5–627 K by the torsion-effusion method are represented by the Equation: Log p (kPa) = (11.30 ± 0.30) − (8290 ± 100)/T. At high temperature, the anilite vaporizes incongruently according to the Equation: 16Cu1.75S(s) → 14Cu2S(s) + S2(g), and the sulfur pressures are well represented in the temperature range 770.5–877 K by the Equation: Log p (kPa) = (10.49 ± 0.40) − (11470 ± 300)/T. The enthalpies associated with these reactions are, ΔH°298 = 178 ± 4 kJ mol−1 and 268 ± 7 kJ mol−1 for reactions 1 and 2 respectively, obtained from second- and third-law treatment of the data. From these reactions, the heat of formation of Cu1.75S, ΔformH°298 = −74 kJ mol−1, was derived.
Vincenzo Piacente - One of the best experts on this subject based on the ideXlab platform.
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Vapor Pressure of Zirconium Tetrafluoride
Journal of Chemical & Engineering Data, 2011Co-Authors: Bruno Brunetti, Vincenzo Piacente, Paolo ScardalaAbstract:Measurements were made of the vapor pressures of zirconium tetrafluoride by using a torsion effusion apparatus. The temperature dependence fit the Equation: Log(p/Pa) = (15.20 ± 0.15) − (11 900 ± 200)/(T/K) (from 685 to 828 K). The compound vaporizes congruently in the monomeric form. With treatment of the measured vapor pressures by second- and third-law methods, the standard sublimation enthalpy ΔsubH°(298 K) = (239 ± 2) kJ·mol−1 was obtained.
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Some Thermodynamic Properties of C76 and C84
The Journal of Physical Chemistry B, 1997Co-Authors: Bruno Brunetti, Guido Gigli, Edoardo Giglio, Vincenzo Piacente, Paolo ScardalaAbstract:The vapor pressures of C76 were measured over the temperature range 834−1069 K by the torsion−effusion method. The results are well represented by the following linear Equation: Log(p/kPa) = (8.23...
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Study on sulfur vaporization from covellite (CuS) and anilite (Cu1.75S)
Journal of Alloys and Compounds, 1994Co-Authors: Bruno Brunetti, Vincenzo Piacente, Paolo ScardalaAbstract:Abstract Covellite decomposes according to the reaction: 4.667CuS → 2.667Cu1.75S(S) + S2(g). The sulfur vapour pressures measured in the temperature range 551.5–627 K by the torsion-effusion method are represented by the Equation: Log p (kPa) = (11.30 ± 0.30) − (8290 ± 100)/T. At high temperature, the anilite vaporizes incongruently according to the Equation: 16Cu1.75S(s) → 14Cu2S(s) + S2(g), and the sulfur pressures are well represented in the temperature range 770.5–877 K by the Equation: Log p (kPa) = (10.49 ± 0.40) − (11470 ± 300)/T. The enthalpies associated with these reactions are, ΔH°298 = 178 ± 4 kJ mol−1 and 268 ± 7 kJ mol−1 for reactions 1 and 2 respectively, obtained from second- and third-law treatment of the data. From these reactions, the heat of formation of Cu1.75S, ΔformH°298 = −74 kJ mol−1, was derived.
Michael H. Abraham - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen bonding: XXVII. Solvation parameters for functionally substituted aromatic compounds and heterocyclic compounds, from gas—liquid chromatographic data
Journal of Chromatography A, 1993Co-Authors: Michael H. AbrahamAbstract:The truncated solvation Equation Log SP = c + rR2 + l Log L16 has been applied to a very large number of sets of gas—liquid chromatographic data on non-polar stationary phases. Here, Log SP can be Log VG or can be the retention index I. R2 is the excess molar refraction of the solute and c, r and l are constants. A set of solutes of known Log L16 values is used to construct the Equation, and then further values of Log L16 can be obtained for any solute of known Log SP value. In this way, new Log L16 values for over 1000 solutes have been obtained. Then knowing Log L16, and R2, the Equation Log SP = c + rR2 + sπ2H + l Log L16 (s is a constant) can be applied to GLC data on polar non-acidic stationary phases, and the dipolarity/polarisability parameter, π2H determined similarly. Values of π2H for over 700 compounds are reported, including those for functionally substituted aromatic compounds and heterocyclic compounds. It is shown that π2H, is a blend of dipolarity/polarisability, and cannot simply be calculated from solute dipole moments.
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Hydrogen bonding: XXI. Solvation parameters for alkylaromatic hydrocarbons from gas-liquid chromatographic data
Journal of Chromatography A, 1992Co-Authors: Michael H. Abraham, Gary S. WhitingAbstract:Abstract The truncated solvation Equation Log SP = c + rR2 + lLog L16 has been applied to numerous sets of gas-liquid chromatographic (GLC) data for alkylaromatic hydrocarbons on non-polar stationary phases. Here SP can be VG or can be the relative retention time, and the retention index I can in this context be used in place of Log SP. R2 is the solute excess molar refraction, easily obtained from refractive index. A set of solutes of known Log L16 is used to set up the Equation and then values of Log L16 can be back-calculated for other solutes: L16 is originally defined as the solute gas-liquid partition coefficient on hexadecane at 25°C. Through the above Equation Log L16 values were calculated for 190 solutes. Once Log L16 is known, the reduced Equation Log SP = c + sπH2 + lLogL16 can be applied to GLC data on polar stationary phases, and the dipolarity/polarizability parameter πH2 obtained by back-calculation in a similar way. Values of πH2 for 120 solutes are listed. It is shown that n-alkyl substituents affect the πH2 value only slightly, but ortho substituents considerably increase πH2, e.g., benzene (0.52), toluene (0.52), o-xylene (0.56), 1,2,3-trimethylbenzene (0.61), 1,2,3,4-tetra-methylbenzene (0.65), pentamethylbenzene (0.66), hexamethylbenzene (0.72).
Corwin Hansch - One of the best experts on this subject based on the ideXlab platform.
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MOLECULAR ORBITAL PARAMETERS AND COMPARATIVE QSAR IN THE ANALYSIS OF PHENOL TOXICITY TO LEUKEMIA CELLS
Journal of the Chemical Society Perkin Transactions 2, 1998Co-Authors: Litai Zhang, Hua Gao, Corwin Hansch, Cynthia Dias SelassieAbstract:Evidence is presented for a new type of phenol toxicity that is correlated with the parameter σ+ or HOMO–LUMO gap calculations. The correlation Equation: Log 1/C = –1.58σ+ + 0.21Log P + 3.10 is based mostly on monosubstituted phenols, but more complex estrogenic phenols such as bisphenol A, diethylstilbestrol and estradiol are also well fit. Comparison with radical QSARs suggests that a radical mechanism may be involved.
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The importance of hydrophobicity in the mutagenicity of methanesulfonic acid esters with Salmonella typhimurium TA100.
Chemical research in toxicology, 1993Co-Authors: Asim Kumar Debnath, Corwin HanschAbstract:The analysis of the mutagenic activity of a series of 15 methanesulfonate esters with Salmonella typhimurium TA100 shows that it can be correlated with the following Equation: Log TA100 = 1.10 Log P + 0.73 Log MMI -2.53, where MMI is the relative rate of reaction of the esters with N-methyl-2-mercaptoimidazole and P is the octanol/water partition coefficient. The results are compared with a number of other structure-activity studies on mutagenesis by a variety of types of chemicals.