Computer calculation of liquid-junction potentials—II. Junction potentials for junctions with concentrated KCl

Abstract

Junction potentials for KCl (4 M) ∥ MY where MY is LiCl, NaCl, KBr or KF concentration from 0.0001 to 5.7 M, for KCl (satd)∥HCl, with HCl ranging in concentration from 0.1 to 6 M, and for KCl(satd)∥Z where Z is CaCl 2, LaCl 3, or K 2SO 4, ranging in concentration from 0.001 to 4 M, have been calculated using the concentration profiles derived by the methods described in Part I and including the dependence of activity coefficients and transference numbers upon solution composition in the calculations. Satisfactory agreement was found between residual junction potentials derived from cell emfs of cells containing double-junctions, for example Z( m 1)∥KCl∥Z( m 2), and residual junction potentials predicted from the difference between the calculated values of the two junction potentials. Measurements of the cell emfs of the chain HCl (0.1M)∥KCl (satd)∥NBS pH standard were used to provide residual junction potentials from which junction potentials for KCl (satd)∥NBS pH standards were then found by subtracting the junction potential calculated for HCl (0.1 M)∥KCl (satd).