The preparation of a fast response Ag/Ag2SO4 reference electrode

Abstract

A procedure for the preparation of a fast response Ag/Ag(2)SO(4) reference electrode to be used for the detection of the endpoint of a coulometric titration is described.

On the stability of the silver/silver sulfate reference electrode

“…Note that the measured standard potential for this electrode is 0.350 V vs. SCE, whereas previous works have reported somewhat higher potentials vs. SCE (approximately 0.413 V). 7,10 An intermediate value, 0.39 V vs. SCE, is predicted on the basis of the Ag 2 SO 4 solubility product quoted above. The remaining chloride impurities, which were not removed via the purification procedure, are still likely to interfere with the Ag/Ag 2 SO 4 electrode below this concentration limit.…”

“…1 Rahmel documented the use of a Ag/Ag 2 SO 4 reference electrode in molten salt mixtures at 625 C. 9 Finoly et al presented an extensive and time consuming procedure for Ag/Ag 2 SO 4 electrode preparation from silver oxide paste and sulphuric acid solution. 10 Finally, Ruetschi has developed an Ag/Ag 2 SO 4 electrode for application in lead-acid batteries. 11 Although some of the researchers attempted to record the electrode potential stability with time, none of the reports studied the potential response with the sulfate anion concentration, despite the fact that a commercial Ag/Ag 2 SO 4 electrode is available.…”