Abstract
The standard potential of Se (IV) /Se (VI) couple has been obtained by cyclic voltametry in the relatively pure system.
The formal potentials of the selenium redox reaction have been determined in NaClO4 medium of various ionic strength (I (mol·kg-1) =0.500, 1.00, 1.50, 2.00) at room temperature. These data have been interpreted by using the Specific Ion Interaction Theory to give the following standard potential. In addition, the reactive chemical species have been identified by the dependence of peak potential of oxidation wave on Se concentration. As a result, the following standard potential was determined:
HSeO3- + H2O = SeO42- + 3H+ + 2e-, E0 = 0.821±0.167 V vs. SHE.
This standard potential is consistent with the other experimental study which confirmed the existence of Se (VI) in the potential region which is inconsistent with the selected value by OECD/NEA.