The Precise Coulometric Titration of the Acidic Primary Standard using Amperometric End-point Detection

The sensitive amperometric end-point procedure (Anal. Chem., 23, 1662 (1951)) with an antimony electrode is used in the titrations of acids. The cyclic voltammetric curves of the electrode indicate the possibility of the use of the above method for the titration of acids. The purities of potassium biphthalates (primary standard substances) are determined directly by precise coulometric titration with this end-point location. The standard deviations of the results (99.999%) are 0.007 or 0.008%. The purity of the benzoic acid prepared as the standard material for the calorimeter is also determined by this method. The standard deviation of these results (99.993%) is 0.009%.