On the validity of the polarographic determination of stability constants of metal ions in the case of adsorbable electroactive species

Abstract

The idea that anion-induced adsoprtion of the electroactive species might interfere with the determination of stability constants via shifts in the half-wave potential is critically examined. It is shown that this adsorption occurs only if the standard thermodynamic potential at the electrode-solution interface differs from that in the solution. The final conclusion is that the position of the reversible half-wave potential is not influenced by the adsorption of the electroactive species if the reactions between the complexes, and all adsorption phenomena, proceed infinitely fast.