Voltammetric study of mixed ligand complex formation of lead in simulated salt lake water

Abstract

Differential pulse anodic stripping voltammetry (DPASV) has been employed to study the mixed ligand complexes of lead with carbonate, hydroxide, chloride and fluoride ligands. The single ligand complexes of lead with these ligands were studied initially. Several complexes, were obtained for each simple system: the hydroxo complexes PbOH⁺, Pb(OH)°, and Pb(OH)₃° with mean stability constants of log β ₁ = 0.301, log β ₂ = 0.398 and log β = 2.462 respectively; carbonate complexes PbCO₃° and Pb(CO₃)₂ ² with mean stability constants logß₁ = 3.535 and log β ₂ = 5.394; fluoro complexes PbF⁺ and PbF₂° with stability constants of log β₁  = 1.176 and log β₂  = 3.00 respectively; chloro complexes PbCl⁺, PbCl₂° and PbCl₃ ⁻ with average stability constants of log β ₁ = –0.301, log β₂  = 0.398 and log β₃  = 2.462 respectively. At 25°C in our 0.65 ionic strength, we obtained the following results with the mixed ligands systems:

Keywords:

• Single ligands
• Mixed ligands
• Voltammetry
• Salt lake water

Acknowledgements

The authors wish to acknowledge the financial and material support offered by Norwegian government, NUFU, which made these studies possible. We also thank Norah Nalubowa for typing the work.