Experimental studies of the liquid junction potential between electrolyte solutions in different solvents part IV. A study using mixed-solvent salt bridges

The problem of the liquid junction potential (ljp) between different solvents was studied by measuring the emf's of a cell with a mixed-solvent salt bridge: Ag65 mM AgClO₄, 5 mM Et₄NClO₄ (S₁);1 mM Et₄ NClO₄ (S₁); 0.1 M MX (S₃ + S′₃); 1 mM Et₄NClO₄ (S₂);5 mM Et₄NClO₄, 5 mM AgClO₄ (S₂)6Ag. For 130 different combinations of solvents S₁, S₂, and (S₃+S′₃), the emf's were measured by changing the composition of (S₃ + S′₃) from pure S₃ to S′₃. Though there were exceptions, the emf's in many cases changed linearly or nearly linearly with the volume fraction of the mixed solvents. It was considered that the results were obtained because the component of the Ijp which was due to the solvent-solvent interactions at the mixed solvent/pure solvent junctions often changed in linear or near-linear relations with the volume fraction of the mixed solvent. A preliminary experiment showed some possibility of similar relations also to hold for mixed solvent/mixed solvent junctions.