Association constants for the formation of lead (II) chloride complexes were studies in aqueous solutions also containing copper (II) and cadmium (II) ions.
The ionic strength was adjusted with sodium perchlorate to resemble that of sea water. The temperature was set at fixed values between 5° and 35° C to determine the effect on the equilibria in these systems. The total metal concentration was less than 10-8 M.
Differential pulse anodic striping voltammetry was used with a conventional three electrode system and a thin-film working electrode of Pt/Hg. Complex formation was followed as a function of the ligand concentration by observing the shift in the stripping peak potential Ep.
The measured Ep and temperature data were used to obtain thermodynamic information on the formation of the complex ions. The activity coefficients were assumed constant at a given temperature.
The values for the base ten logarithm of the overall formation constants at 25.0° are 1.11, 1.48 and 1.83 for PbCl+, PbCl°2 and PbCl-3 complexes respectively. These results are in good agreement with literature values. The Δ H of formation values for those complexes in solution were found to be positive. Tentative results were obtained for copper (II) which was only weakly complexed with Cl
- under the present conditions.
| Identifer | oai:union.ndltd.org:pacific.edu/oai:scholarlycommons.pacific.edu:uop_etds-1481 |
| Date | 01 January 1984 |
| Creators | Zamora, Jose Vinicio Macias |
| Publisher | Scholarly Commons |
| Source Sets | University of the Pacific |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | University of the Pacific Theses and Dissertations |
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