Influence of pH on Lead Chlorofluoride Precipitation

Formation of Lead Chloride Fluoride at Lower pH Values for Gravimetric Purposes.

“…(5) Landolt-Bornstein, "Numerical Values and Functions," 6th ed., Vol. (7) Plumb, R. C., Martell, A. E., Bers-worth, F. C., J. Phys. Chem.…”

“…The procedures based on titration of chloride in the precipitate have shown appreciable deviations in results obtained. In 1949, Kaufman (7) reported that insufficient control of pH may be responsible for this. In studies of the Hoffman and Lundell (4, 5) method, he concluded that the pH should be maintained between 4.6 and 4.7 for satisfactory results.…”

“…each were then taken. In one the chloride was determined by addition of excess standard silver nitrate followed by back-titration with 0.LV KCNS [modified Volhard method of Caldwell and Moyer (7)] using a 10-ml. microburet.…”

Rapid Determination of Fluorine, Sulfur, Chlorine, and Bromine in Catalysts with Induction Furnace

“…Although thorium nitrate titration is the most common, many different colorimetric methods are also suitable for measuring fluorine absorbed in basic solutions. Gravimetric procedures have also been used (19,28,27), as well as acid-base titrations (3,7,12, 82), amperometric titrations (6,26), indirect polarography (30), oscillometry (15), radioactivity (23,25), and nuclear magnetic resonance (31).…”