Osmotic and activity coefficients of sodium sulphate in water from 150 to 250 °C

Abstract

Osmotic and activity coefficients of sodium sulphate in aqueous solution have been determined at temperatures up to 250 °C, at solute concentration from 0.3 m to saturation, by measurements of vapour pressure using a newly designed high pressure cell. A precision pressure transducer is used in this cell for pressure measurement. Certain thermodynamic quantities have been calculated from the activity coefficients.

Phase Equilibria in Binary and Ternary Hydrothermal Systems

“…and 'Vap.pr.diff' in Table 1.1). In such apparatus the composition is not measured but taken from the initial charge, whereas the vapor pressure is measured directly with a pressure gage (Mashovets et al, 1973;Bhatnagar and Campbell, 1982; Table 1.1 Summary of experimental data on phase equilibria in hydrothermal systems COMMENTS: Each line contains a breaf information about the experimental data obtained for one system or several relevant systems from the publication(s) and in the table(s) collected in the Appendix. This information includes the name of aqueous system (only the non-aqueous component(s) is(are) shown in the 1 st column), the studied types of phase equilibria -Phase equilibria (2 nd column), the experimental methods employed for studies -Methods (3 rd column), the ranges of studied temperature -Temperature (4 th column), pressure -Pressure (5 th column), and composition -Composition (6 th column).…”

Osmotic and activity coefficients of sodium hydroxide in water from 150 to 250.degree.C

“…The experimental procedure and design of the cell for measuring vapor pressures are given elsewhere (10). Special care was taken to ensure that solutions were free from any dissolved C02.…”

“…The vapor pressure of electrolyte solutions is a single (most important) physical property, which can be used to get many other thermodynamic properties such as osmotic and activity coefficients. We have developed a special apparatus for measuring vapor pressures at elevated temperatures; details are to be found In the literature (10). Some work on thermodynamic properties of sodium hydroxide below 100 °C has been reported by Akerlof and Kegeles (11) and Haywood and Perman (12).…”

Comparative Study of Sodium Phosphate and Sodium Sulfate in Aqueous Solutions at (298.15 to 353.15) K

“…They recalculate them in a consistent manner and use the more reliable results to evaluate the parameters of both an Archer-type modified Pitzer model and a similar model using mole fraction compositions. The hygrometric measurements of the aqueous solutions of Na 2 SO 4 ·10H 2 O were also performed at 298.15 K and compared with the literature data. ,,, The summary of available literature data for Na 2 SO 4 (aq) in a molality range at various temperatures, was presented in Table . ,− Indeed, Holmes and Mesmer reported high-temperature isopiestic data from (383.15 to 498.15) K and up to 498.15 K . Isopiestic vapor-pressure measurements were also made by Rard et al at 323.15 K and by Baabor et al , at 313.15 K. The emf studies were given at temperatures from (273.15 to 313.15) K in the molality range (0.075 to 1.3) mol·kg –1 , and for (0.001 to 0.30) mol·kg –1 from (283.15 to 343.15) K …”