Liquid-junction potentials, and relative activity coefficients of chloride ions, in concentrated mixed chlorides and nitrates at 25 degrees C

Definitions of pH Scales.

“…is customarily interposed between the unknown solution and the reference electrode of cell II in an attempt to reduce the magnitude of the junction potentials, and presumabfy the differences among the potentials, between potassium chloride and the many different solutions that are employed as standards and unknowns. A concentrated solution of ammonium nitrate is not as effective as saturated potassium chloride for this purpose (15), but mixed chlorides and nitrates appear to possess certain advantages (106). The bridge solution of potassium chloride is often regarded as reducing the residual liquid-junction potential to a few tenths of a millivolt, when the pH of each solution forming the boundary is greater than 3 and less than 11 (88,123).…”