On the impedance of galvanic cells: XI. The impedance of the Hg/Hg2++ electrode in 1 M and 0.1 M HClO4

The accuracy of the double layer capacity measurements at high potentials described in part IX 1 is critically examined, especially with a view to the correct determination of the ohmic resistance of the cell. A limit for the exchange current density of the redox couple, which can be detected by the method of frequency variation, is determined. The systematic error in the calculated double layer capacity values, if this limit is just reached, is estimated. From impedance measurements in 0.1 M-HClO4 solution it appears that the capacity-potential curve is identical with that in 1 M-HClO4 solution.