Coulometric titration of +2 copper with electrogenerated +2 tin

Using a supporting electrolyte composed of 4 M sodium bromide-0.2 N hydrochloric acid- 0.2 M stannic chloride, and a platinum generator cathode, +2 copper can be titrated accurately to the +1 state with electrogenerated +2 tin. With potentiometric end-point detection, quantities of copper from about 1 to 35 mg in a volume of 90 ml are titratable with an error of ± 0.3%. The titration is applicable in the presence of most of the elements that are commonly associated with Copper.