Hydrolysis of the zinc(II) ion in sodium nitrate, chloride and perchlorate medium: the effect of the anionic medium

Abstract

Hydrolysis of the zinc(II) ion in 0.5 mol dm^–3(Na)NO₃, (Na)Cl or (Na)ClO₄ solution was studied by the electromotive force method at 25 °C. The data cover the zinc(II) concentration range 2.5–40 mmol dm^–3 within the pH range 2.0–6.0. The general least-squares treatment of the data indicates the formation of only mononuclear complexes. The complex [Zn(OH)]⁺ was found in all three media, while Zn(OH)₂(aq) was found only in perchlorate solution. This, as well as the differing values for the stability constant of [Zn(OH)]⁺, demonstrate the effect of the anionic medium on both complex formation and stability of the hydrolytic species.