With alkali, 2nd order kinetics are observed overall, and the reaction can be followed by titrating the remaining alkali with acid.
The total alkali is determined by incinerating a weighed sample in a platinum dish, dissolving the residue in water, filtering and titrating the filtrate with standard acid.
When cadmium is not present the copper may be precipitated by boiling the acidulated ammoniacal solution with test lead and titrating, as before described, without removing the lead and copper from the solution.
The ferrocyanide solution is standardized by dissolving i gramme of pure zinc in 6 cc. of hydrochloric acid, adding ammonium chloride, and titrating as before.
The potassium cyanide solution is standardized by dissolving 0.5 gramme o£ pure copper in 5 cc. of nitric acid, diluting, adding io cc. of ammonia, and titrating exactly as described above.