Thermodynamic study of aqueous rubidium and cobalt selenate system at the temperature 298.15K

Thermodynamics of formation of double salts and mixed crystals from aqueous solutions

“…For most of the systems investigated, the model predicted solubilities in ternary mixtures agree very well with the experimental data obtained by us [27][28][29]33,[36][37][38]54,58,61,62] and those given in the literature . Additional experiments were performed [27][28][29]31,41,44] to check contradictory data reported in the literature and specify the type of the solubility diagrams.…”

“…Note that in constructing the mixed solutions {m 1 FeSO 4 + m 2 Fe 2 (SO 4 ) 3 }(aq) and {m 1 K 2 SO 4 + m 2 Fe 2 (SO 4 ) 3 }(aq) model [65] the pure electrolyte Al 2 (SO 4 ) 3 (aq) parameters from references [57,59] are accepted as an approximation for ferric sulfate binary parameters {valid up to %1 mol kg À1 of Fe 2 (SO 4 ) 3 }. Simulation of the binary solutions of alkali selenates and sodium bichromate was performed on the basis of experimental osmotic coefficients data obtained by us using the isopiestic method [24,26,36,37,56,61]. The comprehensive description of the isopiestic method for determination of a w , and/or / is given in references cited above.…”

Thermodynamics of formation of double salts M2SO4·M′SO4·6H2O and M2SeO4·M′SeO4·6H2O where M denotes Rb, or Cs and M′ denote Co, Ni, or Zn

“…The present paper continues previous experimental (isopiestic and solubility) and thermodynamic studies of the author on binary and complex selenate solutions in which phases with a constant composition (simple and double salts) and solid solutions crystallize [1][2][3][4][5][6][7].…”

“…Comparative analysis of the ternary selenate solutions of the type (m 1 M 2 SeO 4 + m 2 M 0 SeO 4 )(aq) where M denotes Na, K, NH 4 , Rb, or Cs, M 0 denotes Mg, Ni, Co, Zn, Fe, Cu, Mn, or Cd, and m denotes molality, with the corresponding sulphate solutions (m 1 M 2 SO 4 + m 2 M 0 SO 4 )(aq) shows that in most of the cases double salts with the stoichiometric composition 1-1-2, 1-1-4, and 1-1-6 crystallize from the saturated ternary solutions [6][7][8][9][10][11]. The existence of these double salts and its stoichiometric composition depend on the ion radii of the cations {r(M þ ) and r(M 0 2þ )} and of the sulfate and selenate ions [2,3].…”

An isopiestic study of aqueous NaBr and KBr at 50°C: Chemical equilibrium model of solution behavior and solubility in the NaBr–H2O, KBr–H2O and Na–K–Br–H2O systems to high concentration and temperature

“…The osmotic coefficients of the NaBr(aq) and KBr(aq) solutions were determined by the isopiestic method described in our previous studies Ojkova et al, 1999;Barkov et al, 2003). The experimental procedure, method, and apparatus are very similar to those described in the excellent studies of Rard and co-workers (Rard and Archer, 1995) and of ORNL (Oak Ridge National Laboratory) (see Holmes and Mesmer, 1998;Palmer et al, 2002;Gruszkiewicz and Simonson, 2005).…”