Back titration with mercuric nitrate in alkaline medium; analysis of binary mixtures of barium, strontium or magnesium together with lead, cobalt, nickel or copper

Summary Mercuric nitrate has proved to be a suitable back titrant for EDTA solutions in excess of the amounts reacting quantitatively either with one of the tetrad lead, cobalt, nickel or copper in the presence of one of the triad barium, strontium or magnesium atPh 8 or 9, or with both cations atph 11. This behaviour was the basis underlying the analysis of binary mixtures of the possible combinations between cations of the two groups. The end-points were detected potentiometrically with reasonable jumps and with fair agreement with the theoretical equivalence points.