THERMODYNAMIC PARAMETERS FOR THE FORMATION OF DIMERIC HYDROLYTIC SPECIES OF COPPER(II) IN AQUEOUS NACLO4 SOLUTION AT DIFFERENT IONIC STRENGTHS

The hydrolysis of copper(II) has been studied in experimental conditio ns for which polynuclear species are formed prevalently. The study has been carried out by the pH-metric technique at different temperatures and ionic strengths in NaClO4, aqueous solution. As previously report ed in literature, the most important hydrolytic species is Cu-2(OH)(2) (2+). For copper(II) concentrations greater than 75 mmol dm(-3), also the species Cu-2(OH)(3+) is formed in appreciable amount. The formatio n constants of these species have been determined, together with their dependence on ionic strength. The temperature coefficients of equilib rium constants allowed to obtain the relative formation enthalpies. (C ) 1997 Elsevier Science B.V.