Precise conductimetric studies on aqueous solutions of 2:2 electrolytes. Interpretation of new data in terms of the current theories of Pitt and Fuoss

Abstract

New, precise data are reported for the conductivity of magnesium sulphate in water at 25 and 5 0 T . The data are analysed using the Pitts, Fuoss (1975) and Carman conductance equations and the Debye-Huckel and Glueckauf activity coefficient equations. The Fuoss (1975) equation combined with the Debye-Hiickel equation is found to give the best fit of the data, but only over a limited concentration range.

Ion Association in Dilute Aqueous Magnesium Sulfate and Nickel Sulfate Solutions Under Hydrothermal Conditions by Flow Conductivity Measurements

“…The results for K A are plotted in Figures and , along with values obtained by conductance methods from other workers. ,− Values for MgSO 4 determined by Marshall from solubility measurements are included in Figure for comparison. The association constants for both systems show a rapid increase with temperature.…”

“…Temperature dependence of equilibrium constants log( K A ) for the MgSO 4 (aq) system: ●, this work; △, Marshall solubility; ◻, Katayama conductance; ○, Nair and Nancolas EMF; ⧫, Tomsic et al, conductance; ×, Pethybridge and Taba; , eq .…”

“…The results for K A are plotted in Figures 7 and 8, along with values obtained by conductance methods from other workers. 31,[33][34][35] The values for NiSO 4 are higher than those for MgSO 4 by about 0.13 units at 398 K and 0.04 units at 498 K in log K A . The results are consistent with measurements near ambient conditions by Nair and Nancollas 36,37 using electromotive force (EMF) methods and with conductance measurements by Katayama, 31 Tom si c et al, 34 and Be stec-Roga c et al 35 The temperature dependence of the association constants for MgSO 4 and NiSO 4 in Figures 7 and 8 could be represented well by thermodynamic models based on linear heat capacity functions in eq 15.…”

Aqueous hydrochloric acid conductance from 0 to 100.degree.C

“…Limiting molar conductivities for HCI as a function of temperature are tabulated in Table II. These were calculated first with the conductance function proposed by Fuoss in 1975 (16) using a computer program developed by Pethybridge (17) which searched for that value of the distance parameter, R, that would give the best fit of the data to the function. However, the range of concentrations available did not include high enough concentrations to generate a minimum in the residuals of significant depth as the Gurney sphere diameter, R, was varied.…”

Δομή Και Δυναμική Ιοντικών Και Μοριακών Αλληλεπιδράσεων Σε Διαλύματα Μεικτών Οργανικών Διαλυτών

“…74,75 Επίσης, σε υδατικά διαλύματα η σύζευξη ιόντων είναι σπάνια για μονοσθενείς συμμετρικούς ηλεκτρολύτες αλλά είναι πολύ σημαντική για δισθενείς ηλεκτρολύτες. 76 Χαρακτηριστική είναι η παρατήρηση των Pethybridge και Taba, 77 οι οποίοι αναφέρουν ότι διαλύματα συμμετρικών 2:2 ηλεκτρολυτών σε νερό είναι ισοδύναμα με διαλύματα 1:1 ηλεκτρολυτών σε ένα διαλύτη με διηλεκτρική σταθερά ~20. 73,78 Όταν η διηλεκτρική σταθερά του διαλύτη είναι πολύ μικρή (σε μη υδατικούς διαλύτες), οι ηλεκτροστατικές δυνάμεις είναι πολύ ισχυρές, με αποτέλεσμα τα ιοντικά ζεύγη (Μ + Α -), να έλκουν ιόντα για να σχηματίσουν σύμπλεγμα τριών ιόντων [ΜΑΜ] + ή [ΑΜΑ] -:…”