Pairing the potential of a redox couple with the standard hydrogen electrode.

Abstract

The standard electrode potential of redox couples can be calculated by pairing with the standard hydrogen electrode (SHE) to which, by an internationally accepted convention, the value of 0.00 volts is assigned. Since SHE is a somewhat awkward electrode to work with, other reference electrodes can be used for the mentioned purpose. The potential values of these latter are of course paired with the hydrogen standard electrode. A great deal of standard potentials can be calculated by this procedure. The aim of this exercise is to show how to pair a redox couple with the H standard half cell to obtain the former's standard electrode potential. In addition, the user can get a deeper knowledge about galvanic cells concerning the set up of these electrochemical devices and the interpretation of the measured potentials in terms of relative oxidizing/reducing power.