scholarly journals Thermodynamic properties of the liquid Hg-Tl alloys determined from vapour pressure measurements

2002 ◽  
Vol 38 (3-4) ◽  
pp. 237-247 ◽  
Author(s):  
W. Gierlotka ◽  
K. Fitzner ◽  
M. Sukiennik
Keyword(s):  
Thermodynamic Properties ◽  
Activity Coefficients ◽  
Thermodynamic Functions ◽  
Vapour Pressure ◽  
Pressure Measurements ◽  
Temperature Range ◽  
Liquid Solutions ◽  
Partial Vapour Pressure

The partial vapour pressure of mercury over liquid Hg-Tl liquid solutions were determined in the temperature range from 450 to 700 K by direct vapour pressure measurements carried out with the quartz gauge. From the measured ln pHg vs. T relationships activities of mercury were determined. Using Redlich-Kister formulas logarithms of the activity coefficients were described with the following equations: From which all thermodynamic functions in the solutions can be derived.

scholarly journals Evaporation of sulphate aerosols at low relative humidity

2016 ◽  
Author(s):  
Georgios Tsagkogeorgas ◽  
Pontus Roldin ◽  
Jonathan Duplissy ◽  
Linda Rondo ◽  
Jasmin Tröstl ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Thermodynamic Properties ◽  
Sulphuric Acid ◽  
Activity Coefficients ◽  
Vapour Pressure ◽  
Equilibrium Constants ◽  
Cloud Chamber ◽  
Aerosol Dynamics ◽  
Sulphate Aerosols

Abstract. Here we explore the vapour pressure of sulphuric acid at very low relative humidity, where evaporation of sulphuric acid from particles can be important in the atmospheres of Earth and Venus. We performed experiments in the CLOUD chamber at CERN forming sulphuric acid particles via nucleation and then measuring evaporation versus temperature and relative humidity. We modelled the experiments with the ADCHAM model to constrain the thermodynamic properties governing the evaporation of sulphuric acid. ADCHAM includes a thermodynamics module coupled to an aerosol dynamics module. We derived the mole fractions and activity coefficients of H2SO4, HSO4−, SO42− and SO3 in the particles and then simulated the condensation and evaporation of H2SO4 and SO3. We constrained the equilibrium constants for the dissociation of H2SO4 to HSO4− (KH2SO4) and the dehydration of H2SO4 to SO3 (xKSO3). Our results suggest that particle shrinkage is mainly governed by H2SO4 evaporation, however, we cannot dismiss a contribution from SO3 evaporation. We conclude that KH2SO4 = 2–4 ∙ 109 mol ∙ kg−1 at 288.8 ± 5 K and xKSO3 ≥ 1.4 ∙ 1010.

Heat Capacity and Thermodynamic Properties of LaBr3 at 300 – 1100 K

2004 ◽  
Vol 59 (11) ◽  
pp. 825-828
Author(s):  
L. Rycerz ◽  
E. Ingier-Stocka ◽  
B. Ziolek ◽  
S. Gadzuric ◽  
M. Gaune-Escard
Keyword(s):  
Differential Scanning Calorimetry ◽  
Heat Capacity ◽  
Thermodynamic Properties ◽  
Temperature Dependence ◽  
Enthalpy Of Formation ◽  
Thermodynamic Functions ◽  
Molar Enthalpy ◽  
Standard Molar Enthalpy ◽  
Scanning Calorimetry ◽  
Temperature Range

The heat capacity of solid and liquid LaBr3 was measured by Differential Scanning Calorimetry (DSC) in the temperature range 300 - 1100 K. The obtained results were fitted by a polynomial temperature dependence. The enthalpy of fusion of LaBr3 was also measured. By combination of these results with the literature data on the entropy, S0m (LaBr3, s, 298.15 K) and the standard molar enthalpy of formation, ΔformH0m (LaBr3, s, 298.15 K), the thermodynamic functions of lanthanum tribromide were calculated up to 1300 K

Excess free energies of mixing at temperatures below 25°. Isopiestic measurements on the systems H2O-NaCl-Na2SO4 and H2O-NaCl-MgSO4

1971 ◽  
Vol 24 (12) ◽  
pp. 2487 ◽  
Author(s):  
CW Childs ◽  
RF Platford
Keyword(s):  
Free Energy ◽  
Vapour Pressure ◽  
Excess Free Energy ◽  
Pressure Measurements ◽  
Experimental Uncertainty ◽  
Free Energies ◽  
Isopiestic Measurements ◽  
Temperature Range ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

Isopiestic vapour pressure measurements have been made on the systems H2O-NaCl-Na2SO4 and H2O-NaCl-MgSO4 at 15� and 0�. Excess free energies of mixing the aqueous salts hare been calculated for various ionic strengths, and the results have been compared with those previously obtained at 25�. ��� Within experimental uncertainty the excess free energies of mixing of aqueous NaCl with aqueous Na2SO4 are the same at 0�, 15�, and 25�. However, the excess free energy of mixing aqueous NaCl with aqueous MgSO4 shows differences which may be just larger than experimental uncertainty over the same temperature range.

Thermodynamic properties of the alkali metal hexachloroniobate and hexachlorotantalate compounds by vapour pressure measurements

1978 ◽  
Vol 56 (19) ◽  
pp. 2538-2545 ◽  
Author(s):  
Donald R. Sadoway ◽  
S. N. Flengas
Keyword(s):  
Thermodynamic Properties ◽  
Alkali Metal ◽  
Metal Cation ◽  
Vapour Pressure ◽  
Binary Systems ◽  
Alkali Metal Cation ◽  
Pressure Gauge ◽  
Pressure Measurements ◽  
Partial Pressures ◽  
Fused Quartz

The vapour pressures for the decomposition of the solid and liquid compounds AMCl6 where A = Na, K, Rb, or Cs, and M = Nb or Ta, were measured by a fused quartz Bourdon spiral pressure gauge. The hexachlorotantalates were found to be more stable thermally than the hexachloroniobates. Enthalpies of decomposition were calculated. The dissociation temperatures of each sequence of compounds increase with increasing size of the radius of the alkali-metal cation. Partial pressures of NbCl5 or TaCl5 vapour in equilibrium with solutions representing the binary Systems KCl–KNbCl6 and KCl–KTaCl6, respectively, are also reported.

Vapour Pressure and Activity Coefficients of Dilute 2,2,4 Trimethylpentane(Isooctane)-Acetone Mixtures

1970 ◽  
Vol 25 (1) ◽  
pp. 45-47
Author(s):  
J. Edwards ◽  
M.V. Encina
Keyword(s):  
Activity Coefficients ◽  
Vapour Pressure ◽  
Pressure Measurements ◽  
Raoult’S Law ◽  
Azeotropic Point ◽  
Raoult's Law

Abstract Vapour pressure measurements are carried out to test Raoult's law at extreme concentrations, and the deviations are reported. - The azeotropic point is measured and qualitative discussions are presented.

Thermodynamic properties of (n-alkoxyethanols + organic solvents). XII. Total vapour pressure measurements for (n-hexane,n-heptane or cyclohexane + 2-methoxyethanol) at different temperatures

2001 ◽  
Vol 33 (1) ◽  
pp. 47-59 ◽  
Author(s):  
F.Javier Carmona ◽  
Venkat R. Bhethanabotla ◽  
Scott W. Campbell ◽  
J. Antonio González, ◽  
Isaías García de la Fuente ◽  
...  
Keyword(s):  
Thermodynamic Properties ◽  
Organic Solvents ◽  
Vapour Pressure ◽  
Pressure Measurements ◽  
Different Temperatures

Determination of Activity Coefficients from total pressure measurements

1953 ◽  
Vol 6 (3) ◽  
pp. 207 ◽  
Author(s):  
JA Barker
Keyword(s):  
Least Squares ◽  
Activity Coefficients ◽  
Vapour Pressure ◽  
Total Pressure ◽  
Pressure Measurements ◽  
Method Of Least Squares ◽  
Determination Of Activity

A method of least squares is described for calculating activity coefficients from results of total vapour pressure measurements.

Activity coefficients and solubilities of the system (Ag/Cs)NO3-H2O from vapour pressure measurements

1997 ◽  
Vol 101 (8) ◽  
pp. 1129-1135 ◽  
Author(s):  
Jürgen Geerlings ◽  
Joachim Richter ◽  
Lisbeth Rørmark ◽  
Harald A. Øye
Keyword(s):  
Activity Coefficients ◽  
Vapour Pressure ◽  
Pressure Measurements
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