Change search
ReferencesLink to record
Permanent link

Direct link
Chemical speciation of environmentally significant metals with inorganic ligands. Part 5: The Zn2+ + OH, Cl, CO32–, SO42–, and PO43– systems (IUPAC Technical Report)
Show others and affiliations
2013 (English)In: Pure and Applied Chemistry, ISSN 0033-4545, E-ISSN 1365-3075, Vol. 85, no 12, 2249-2311 p.Article in journal (Refereed) Published
Abstract [en]

The numerical modeling of ZnII speciation amongst the environmental inorganic ligands Cl, OH, CO32–, SO42–, and PO43– requires reliable values for the relevant stability (formation) constants. This paper compiles and provides a critical review of these constants and related thermodynamic data. It recommends values of log10 βp,q,r° valid at Im = 0 mol·kg–1 and 25 °C (298.15 K), and reports the empirical reaction ion interaction coefficients, ∆ε, required to calculate log10 βp,q,r values at higher ionic strengths using the Brønsted–Guggenheim–Scatchard specific ion interaction theory (SIT). Values for the corresponding reaction enthalpies, ∆rH, are reported where available. There is scope for additional high-quality measurements for the Zn2+ + H+ + CO32– system and for the Zn2+ + OH and Zn2+ + SO42– systems at I > 0. In acidic and weakly alkaline fresh water systems (pH < 8), in the absence of organic ligands (e.g., humic substances), ZnII speciation is dominated by Zn2+(aq). In this respect, ZnII contrasts with CuII and PbII (the subjects of earlier reviews in this series) for which carbonato- and hydroxido- complex formation become important at pH > 7. The speciation of ZnII is dominated by ZnCO3(aq) only at pH > 8.4. In seawater systems, the speciation at pH = 8.2 is dominated by Zn2+(aq) with ZnCl+, Zn(Cl)2(aq), ZnCO3(aq), and ZnSO4(aq) as minor species. This behaviour contrasts with that for CuII and PbII for which at the pH of seawater in equilibrium with the atmosphere at 25 °C (log10 {[H+]/c°} ≈ 8.2) the MCO3(aq) complex dominates over the MCln(2–n)+ species. The lower stability of the different complexes of ZnII compared with those of CuII, PbII, and CdII is also illustrated by the percentage of uncomplexed M2+ in seawater, which is ca. 55, 3, 2, and 3.3 % of [MII]T, respectively.

Place, publisher, year, edition, pages
2013. Vol. 85, no 12, 2249-2311 p.
Keyword [en]
chemical speciation; environmental chemistry; inorganic ligands; IUPAC Analytical Chemistry Division; stability constants; zinc.
National Category
Chemical Sciences
URN: urn:nbn:se:umu:diva-85447DOI: 10.1351/PAC-REP-13-06-03OAI: diva2:693556
Available from: 2014-02-04 Created: 2014-02-04 Last updated: 2014-02-06Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Sjöberg, Staffan
By organisation
Department of Chemistry
In the same journal
Pure and Applied Chemistry
Chemical Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 74 hits
ReferencesLink to record
Permanent link

Direct link