Electrogravimetry and Coulometry

Here the most important techniques are voltammetry, electrogravimetry and coulometry. 

Electrogravimetry and Coulometry - Methods that Completely Electrolyze Electroactive Species 1143... 

A method that completely electrolyzes the substances under study is used in electrogravimetry and coulometry. The method is also useful in electrolytic separations and electrolytic syntheses. Electrolysis is carried out either at a controlled potential or at a controlled current. 

In the electrogravimetry and coulometry described in Section 5.6, the substance under study is completely electrolyzed in obtaining the analytical information. A complete electrolysis is also carried out in electrolytic syntheses and separations. Electrolytic methods are advantageous in that they need no chemical reagent and in that optimum reaction conditions can easily be obtained by controlling electrode potentials. 

Electrogravimetry and coulometry are moderately. sensitive and among the most accurate and precise techniques available to the chemist. Like the gravimetric techniques discussed in Chapter 12, electmgravimetiy requires no preliminary calibration against chemical standards becau.se the functional relationship between... 

Electrogravimetry and coulometry can often exhibit accuracies of a few parts per thousand. 

The following cell has been used for the determination of cadmium in the presence of chloride ions by both electrogravimetry and coulometry. 

Chapter 22 Bulk Electrolysis Electrogravimetry and Coulometry 633 Chapter 23 Voltammetry 665... 

Part IV is devoted to electrochemical methods. After an introduction to electrochemistry in Chapter 18, Chapter 19 describes the many uses of electrode potentials. Oxidation/reduction titrations are the subject of Chapter 20, while Chapter 21 presents the use of potentiometric methods to obtain concentrations of molecular and ionic species. Chapter 22 considers the bulk electrolytic methods of electrogravimetry and coulometry, while Chapter 23 discusses voltammetric methods including linear sweep and cyclic voltammetry, anodic stripping voltammetry, and polarography. 

Instrumentation for Electrogravimetry and Coulometry The basic apparatus required is a power supply (potentiostat with a DC output voltage), an inert cathode and anode (usually platinum foil, gauze, or mesh), and arrangements for stirring. Sometimes a heater is used to facilitate the processes. 

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