Water Activities and Equilibrium Phase Behavior for the Binary K3PO4(aq), K2SO4(aq) and the Ternary K3PO4 + K2SO4 + H2O Systems at Various Temperatures from 298.15 to 353.15 K

Solubility of Mixed Ternary Systems of Hexafluoridosilicate Salts (M = Na+, K+, or NH4+) in Hexafluoridosilicic Acid Aqueous Solutions at T = 353.15 K

“…The developed model based on ion interaction , is employed to evaluate the thermodynamic properties of the mixed ternary solutions. The osmotic coefficients of the salt aqueous solutions in ternary systems, H 2 [SiF 6 ] and M 2 [SiF 6 ] (M = Na + , K + , or NH 4 + ), with a common anion are calculated by eq where f ϕ is the long-range electrostatic term, defined as and the second virial coefficient B ϕ is given by eq where α = 2.0 kg 1/2 mol –1/2 and b = 1.2 kg 1/2 mol –1/2 .…”

“…The experimental water activity of the mixed ternary systems was measured by the hygrometric method described in earlier works. , The apparatus used in this study of mixed electrolyte solutions is essentially the same as that used for the investigation of aqueous single electrolyte solutions. Indeed, the apparatus has been amended and appropriated to high temperatures, for the measurements at T = 353.15 K. The apparatus was maintained at a constant temperature, and its standard uncertainty was u ( T ) = 0.1 K. The measurement of droplet diameter was made by a microscope with an ocular micrometer equipped with a micrometric screw.…”

Equilibrium Solubility Behavior and Thermodynamic Properties of Potassium and Ammonium Di-Hydrogenophosphate Aqueous Solutions at T = 298.15 K

“…This work is a continuation of our studies on phosphate electrolyte solutions; – in this consideration, the experimental study and thermodynamic modeling of the ternary mixture of potassium and ammonium dihydrogenophosphate were investigated at a temperature of 298.15 K. The main objective is to study the thermodynamic properties and equilibrium solubility of false{ y normalK normalH 2 normalP O 4 + ( 1 − y ) normalN normalH 4 normalH 2 normalP O 4 false} ( a q ) . Using the hygrometric method, water activity measurements were then carried out for the mixed system at total molality from dilute to saturated solutions and at various ionic strength fractions ( y ).…”

“…They make it possible to highlight the sources of information about the structure of solutions as well as the different phenomena and processes involved in solutions. The investigation of KH 2 PO 4 and (NH 4 )­H 2 PO 4 mixed aqueous solutions is of considerable interest; indeed, in our previous work, the binary orthophosphates in aqueous solutions MH 2 PO 4 –H 2 O with M = Na, K, or NH 4 were studied at temperatures ranging from 298.15 to 353.15 K, – in order to understand the phenomena governing the process of binary solutions. The thermodynamic properties of orthophosphate salts in aqueous solutions are greatly dependent on the charge, nature, and size of the ions .…”