Thermodynamics Research Center / ThermoML | Thermochimica Acta

Investigation of Potassium Sulphate - Calcium Sulphate Binary System by Knudsen Effusion Mass Spectrometry

Armatys, K.[Kamila], Bencze, L.[Laszlo], Miller, M.[Miroslaw], Wolter, A.[Albrecht]
Thermochim. Acta 2014, 575, 254-61
ABSTRACT
Vaporisation studies of pure K2SO4 and mixtures of K2SO4 and CaSO4 in the quasi-binary K2SO4-CaSO4 system with Knudsen effusion mass spectrometry resulted in the determination of thermodynamic data. From partial pressures of the gaseous species over condensed phases it was possible to determine the sublimation enthalpies AsubH and the thermodynamic activities of components. The sublimation enthalpy of K2SO4 agrees well with two literature sources. For the first time the experimental data of activities of K2SO4 and CaSO4 in the binary system could confirm theoretical studies.
Compounds
# Formula Name
1 K2O4S potassium sulfate
2 CaO4S calcium sulfate
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 1
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Calculated from knudsen effusion weight loss
  • 138
  • POMD
  • 2
  • 1
  • (Relative) activity - 1 ; Liquid
  • Mole fraction - 1; Liquid
  • Temperature, K; Liquid
  • Liquid
  • Gas
  • MS-Knudsen
  • 98