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 (E_j) 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 E_j 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.