OPEN CIRCUIT POTENTIAL FOR COPPER ELECTRODE IN 1-M NACL SOLUTIONS

The open circuit potential (OCP) of Cu electrode in 1 m NaCl solution was studied under different conditions. These include the change in pH (1-13), temperature (10-50-degrees-C) and the effect of O2, N2 and two organic additives, namely Sodium Methyl Dithiocarbamate and Sodium Butyl Dithiocarbamate. It was found that OCP changes to the positive or negative directions, depending on pH. The effect of temperature was found to depend mainly on pH. The presence of O2 has a pronounced effect on the potential and so is the addition of the two organic additives. The change of potential seems to be complicated since the kinetics of the change was found to be first, second or mixed first and second-order depending on pH. The solid products formed at the electrode surface (pH = 1-9) were identified by IR spectroscopy.