Kimie Izawa

Determination of traces of chlorine in sodium metal by coulometric titration

SummaryProcedures have been developed for the determination of less than 1 ppm of chlorine in sodium. An amalgamation or a vacuum distillation technique is used for the separation of chloride from 3–5 g of sodium. After the separation, the residue is dissolved in ethanol containing perchloric acid and sodium perchlorate, and chloride in the ethanol solution is determined by coulometric titration with mercury ions. The endpoint is determined potentiometrically.ZusammenfassungVerfahren zur Bestimmung von weniger als 1 ppm Chlor in Natrium wurden ausgearbeitet. Amalgamierung oder Vakuumdestillation dienen zur Trennung des Chlorids von 3–5 g Natrium. Der Rückstand nach der Trennung wird in Äthanol gelöst, das Perchlorsäure und Natriumperchlorat enthält. Das in äthanolischer Lösung vorliegende Chlorid wird coulometrisch mit Quecksilber titriert. Der Endpunkt wird potentiometrisch bestimmt.

Determination of Hydrogen Fluoride and Uranium(VI) in Crude Uranium Hexafluoride by Hydrolysis and Potentiometric Titration

A simple method for determining HF and U(VI) in a hydrolyzed solution of UF6 by alkalimetry is described. About 1 g of UF6 was taken in a polytrifluoromonochloroethylene tube, and hydrolyzed with about 50 ml of water in a closed polyethylene bottle. Using a glass electrode, HF in the hydrolyzed solution was titrated potentiometrically with an alkali solution, after the U(VI) had been masked with ammonium sulfate. When the equivalence point for the free acid was reached, hydrogen peroxide was added to the solution and the liberated acid equivalent to U(VI) was titrated with the same standard alkali solution. Assuming that the hydrolysis of UF6 takes place stoichiometrically, the accuracy of this method was roughly evaluated to be ±10% for the ratio of HF/UF6 and ± 1 % for the value of U(VI) in the range of 0 to 1 mole of HF per mole of UF6.