The Vapor Pressures of Saturated Aqueous Solutions of Certain Salts

Abstract

The solubilities of potassium perchlorate and potassium nitrate have been measured in the presence of several added salts in pure glacial acetic acid.The observed solubilities agree with those predicted by the interionic attraction theory if a sufficiently large ion diameter is assumed.An empirical relationship from which the value of the activity coefficient may be calculated has been pointed out.A somewhat better agreement is obtained with the extended theory of Gronwall, La Her and Sandved than with the original Debye-Htickel development.It is concluded that explanation of the properties of salt solutions requires that other properties of the solvent in addition to its dielectric constant must be considered. Cambridge, Massachusetts

Vapor Pressure of Saturated Aqueous Solutions of Potassium Sulfate from 310 K to 345 K

“…These data, which correspond to the temperature range 280 K ≤ T ≤ 323 K, are included in Figure 2. To carry out the comparison, the dependence given in (1), obtained from the correlation of the ours experimental results, was extrapolated up to 280 K. There can be observed in Figure 2 a good agreement between the extrapolation of the correlation (continuous line) and the values of the vapor pressure obtained from the literature [4][5][6][7][8], except those reported by Foote et al These results are lower than those of the other authors in the low temperature range, being the corresponding slope of the dependence ln P versus T significantly greater. The origin of this different behavior is unknown but could probably be due to same kind of systematic error in the experimental determination of pressure.…”

“…From the correlation of the experimental results, the corresponding analytical dependence was derived, which is given by (1). The results obtained were compared with the vapor pressure data reported by Leopold and Johnston [4], Foote et al [5], and Adams and Merz [6]. There were also included vapor pressure values obtained from dew point measurements evaluated by Wexler and Hasegawa [7].…”

“…The quality of the correlation can be appreciated Journal of Thermodynamics 3 by the average value of the relative deviation, which is 0.147%. The regression line was extrapolated to lower values of temperature in order to be compared with experimental results obtained from the literature (the results of [4][5][6][7]). …”

“…Finally, the molar volume of liquid water v o w (T) was calculated from the relationship between water density and temperature given by Kell [15]. The values of the water activity for the saturated solutions of K 2 SO 4 evaluated experimentally are [5]; (AE) [6]; (Á) [7].…”

“…However, for the case of potassium sulfate the available information is surprisingly scarce and restricted to the temperature range 273 K ≤ T ≤ 323 K [4][5][6][7] plus one evaluation at 374 K [8]. On this context, the present work studied experimentally the vapor pressure of saturated aqueous solutions of potassium sulfate from 310 K to 345 K and evaluated from these data the dependence of the water activity on temperature.…”