The oxidation of Cu(I) in air-saturated solutions of seawater has been measured as a function of pH (5.3-8.6), temperature (5-45 °C), and salinity (5-44). The overall rate constant k (kg mol-1 min-1) [formula omitted] has been fitted to [formula omitted] with a standard error of 0.08 in log k. The energy of activation was found to be 45.6 ± 1.7 kJ mol-1. The strong chloride dependence of the rates has been attributed to the effect of temperature and ionic strength on the oxidation of Cu+ and CuCl0 species. At a given Cl- concentration, the rates of oxidation in seawater are lower than in NaCl or NaCl-NaClO4 mixtures. These differences in seawater are due to a decrease in the rates due to Mg2+ and Ca2+ and the increase in the rates due to HCO-3. Possible causes of these effects are discussed.
ASJC Scopus subject areas
- Environmental Chemistry