Liquid junction potentials across the interface between the aqueous saturated calomel electrode and some nonaqueous solvents, based on the tatb assumption

Abstract

The liquid junction potentials (Ej) across aqueous saturated KCl/nonaqueous solvent junctions have been determined within the framework of the tetraphenylarsonium tetraphenylborate (tatb) extra- thermodynamic assumption. The nonaqueous solvents comprise methanol, ethylene glycol, acetonitrile, propylene carbonate, dimethylformamide and dimethyl sulfoxide. The Ej values obtained are fairly small (below 40 mV) in the case of protic solvents and fairly large (within 100-200 mV) in the case of dipolar aprotic solvents, as expected if primarily guided by solvent-solvent interactions across the liquid junctions. The results allow the aqueous saturated calomel electrode to be used to relate electrode potentials in different solvents.