The Determination of Trivalent Chromium in Chromic Acid and in Chromium Plating Baths

Trivalent chromium in chromium plating baths may be determined by oxidation with excess of standard ceric sulfate and titration of the excess with standard sodium nitrite in the presence of the large amount of chromic acid always present. The end point is determined potentiometrically. Moderate amounts of iron, manganese or other common metals cause no interference. The method is much more rapid and accurate than procedures in use at the present time. The same method may be applied in the determination of the percentage of trivalent chromium in chromic acid.