title: Potentiometric study of the protonation equilibrium of Tris(Hydroxymethyl) aminomethane in aqueous sodium perchlorate solutions at 25 degrees C: construction of a thermodynamic model.
abstract: The protonation equilibrium of the Tris(Hydroxymethyl)aminomethane (TRIS) has been studied using an automated potentiometric system. The temperature was kept constant at 25 degrees C and the ionic strength was 0.1, 0.5, 1.0, 2.0 and 3.0 mol dm(-3) in NaClO(4). The experimental constants, obtained at different ionic strengths, were correlated by means of the modified Bromley methodology (MBM) and the thermodynamic protonation constant found to be log (0)beta = 8.07 +/- 0.01 . Those values together with some others for NaCl medium were used to construct a thermodynamic model on both molal and molar scales for the protonation equilibrium of TRIS.
authors.affiliation: Kimika Analitikoaren Departamentua, Euskal Herriko Unibertsitatea, 644 P.K., E-48080, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Gil
authors.forename: M S
authors.initials: MS
authors.lastname: Corbillón
authors.forename: M A
authors.initials: MA
authors.lastname: Olazabal
authors.forename: J M
authors.initials: JM
authors.lastname: Madariaga