ChemInform Abstract: ULTRASONIC RELAXATION STUDIES IN AQUEOUS SOLUTIONS OF ALUMINUM SULFATE AND SCANDIUM SULFATE

Abstract

Die Al‐ und Sosulfatkomplex‐Bildung in wäßriger Lösung wird mit Hilfe von Ultraschall‐Relaxationsmessungen untersucht.

Ion association and hydration in 3:2 electrolyte solutions by dielectric spectroscopy: Aluminum sulfate

“…From the results of the present spectra, and consistent with the evidence provided by pressure-jump (Miceli and Stuehr, 1968;Kalidas et al, 1971) and UA (Bonsen et al, 1978;Kaatze et al, 1999) measurements, it can be concluded that there are three solute-related species present in the solutions that give rise to the three observed lowerfrequency Debye terms. Identification of these species is more difficult than for the relatively straightforward symmetrical (2:2 and 1:1) electrolytes investigated previously Chen et al, 2005;Akilan et al, 2006a,b) because a number of possibilities exist.…”

“…Such a model is also consistent with the number of equilibria established for Al 2 (SO 4 ) 3 (aq) by pressure-jump and ultrasonic absorption experiments (Kalidas et al, 1971;Bonsen et al, 1978). With one exception, the resulting reduced error function v 2 r , which is normalized with respect to the number of adjustable parameters (Schrö dle et al, 2004), was significantly lower for the n = 5 fits than for those with n = 4.…”

“…Ion association in aluminum sulfate solutions has been studied by potentiometry using various electrodes (Sharma and Prasad, 1970;Matsushima et al, 1988;Ridley et al, 1999;Xiao et al, 2002), conductivity (Nishide and Tsuchiya, 1965), solubility (Ridley et al, 1999), calorimetry (Lo et al, 1982), ultrasonic absorption (Bonsen et al, 1978;Kaatze et al, 1999), stopped-flow (Knoche and Ló pez-Quintela, 1983), and pressure/temperature jump (Miceli and Stuehr, 1968;Kalidas et al, 1971) methods. Spectroscopic techniques such as NMR (Akitt et al, 1969(Akitt et al, , 1972(Akitt et al, , 1985Jin and Ichikawa, 1988;Akitt and Howarth, 1989), Raman Schö nherr, 1989, 1991a,b;Rudolph and Mason, 2001) and UV-vis (Kryzhanovskii et al, 1971;McIntyre et al, 1982) have also been employed.…”

“…The method most widely employed to date to study the stepwise formation of ion pairs is variable-frequency ultrasonic absorption, UA (Atkinson and Petrucci, 1966;Bonsen et al, 1978;Kaatze et al, 2000). Such measurements have provided great insights into the kinetics of formation and dissociation of ion pairs, revealing reaction times ranging from diffusion-controlled (nanoseconds) to many tens of seconds (Kaatze et al, 2000).…”

“…Unfortunately, no other studies report concentrations of the solvent-separated species at higher ionic strengths. In particular, the few ultrasonic adsorption studies (Bonsen et al, 1978;Kaatze et al, 1999) are marred by conflicting band assignments and they focus more on kinetic aspects.…”