To compile and critically evaluate the solubilities of the lead carbonates. Reliable information on solubilities in aqueous media is especially valuable for the determination of internally consistent sets of thermodynamic data for lead carbonates. These data are needed for the modeling of geochemical and industrial processes as well as of compositions of ground and waste waters.
A general method for the critical evaluation of solubility data of sparingly-soluble metal carbonates will be applied. It allows the optimization of thermodynamic properties of properly characterized solid phases. The Gibbs energy minimization program ChemSage will be used for the simultaneous analysis of the compiled literature data valid at various temperatures. In contrast to calorimetric methods, such as solution calorimetry or drop calorimetry, the thermodynamic analysis of derived solubility constants (lg K°ps0 = F(T) ) avoids systematic errors inherent to metal ion – water – carbon dioxide systems. In favorable cases this method yielded the enthalpy of solution with an estimated uncertainty of ±3 kJ·mol-1 at 298.15 K.
Depending on the parameters available the Davies approximation, the specific ion – interaction theory, and the Pitzer concept will be used for extrapolation of solubility constants to zero ionic strength. Thus, the interference of both non-specific and specific ion inter-actions will be minimized and data measured in different electrolyte media will become comparable within their experimental error.
Solubility curves (lg (m (Mz+)tot /m°) vs. pH) will be constructed and the respective solid phases will be discussed taking into account geochemical, industrial and environmental aspects.
May 2016 update – Literature search is complete, missing is just the search for the year 2015-2016. Data began to be critically evaluated for cerussite, hydrocerussite, and plumbonacrite.
In July 2016, most of the task group members will participate at the SSED meeting in Geneva, Switzerland, held in connection with the ISSP conference. During the meeting, the task group will review the work that has been developed.
The intended output includes IUPAC-NIST Solubility Data Series. Metal Carbonates. Part 2. Lead carbonates to be submitted for publication in JPCRD, and a paper on the solubility of plumbonacrite.
Page last update 27 May 2016