Potentiometric and spectrophotometric study of the solution equilibria in the nickel(II)–diethanolamine–water system in aqueous sodium perchlorate solutions at 25 °C

Abstract

The acid–base and complexation equilibria of the system nickel(II)-diethanolamine–water have been studied using and automated potentiometric–spectrophotometric titration system at 25 °C and at four ionic strengths (0.5, 1.0, 2.0 and 3.0 mol dm^–3) in NaClO₄ medium. The stoichiometric stability constants, obtained at the different ionic strengths, were correlated by means of the modified Bromley methodology and the corresponding thermodynamic constants were: log ⁰β₀₁₁= 8.88 ± 0.02, log ⁰β₁₁₀= 2.67 ± 0.02 and log ⁰β₁₂₀= 4.42 ± 0.05.