Volumetric Complexometric Method to Determine Sulfate Content in Chromium Plating Solution

摘要

The complexometric method involves the use of glycerin, in the presence of HCI (1:1), to reduce chromium (VI) to chromium (III). Sulfate is precipitated by barium in the presence of Cr (III) and the sediment separated by centrifuging when the solution is separated from precipitated barium sulfate by means of vacuum suction. The precipitate is dissolved with excess EDTA in ammonium environment, using heating block, and unreacted EDTA is back titrated with standardized magnesium chloride.