Gravimetry electrogravimetry

Electrochemistry, in general, is a technique that lends itself to be combined with other techniques. One such technique is gravimetry. Electrogravimetry, discussed earlier in the chapter, is a technique that relies upon the application of a current or potential to deposit an electroactive species onto an electrode. After the material is deposited, its mass is determined analytically. A quartz crystal microbalance (QCM) is an instrument that monitors mass changes in real time. 

Determination. The most accurate (68) method for the deterrnination of copper in its compounds is by electrogravimetry from a sulfuric and nitric acid solution (45). Pure copper compounds can be readily titrated using ethylene diamine tetracetic acid (EDTA) to a SNAZOXS or Murexide endpoint. lodometric titration using sodium thiosulfate to a starch—iodide endpoint is one of the most common methods used industrially. This latter titration is quicker than electrolysis, almost as accurate, and much more tolerant of impurities than is the titration with EDTA. Gravimetry as the thiocyanate has also been used (68). 

The quantitative execution of chemical reactions is the basis of the traditional or classical methods of chemical analysis gravimetry, titrimetry and volumetry. In gravimetric analysis the substance being determined is converted into an insoluble precipitate which is collected and weighed, or in the special case of electrogravimetry electrolysis is carried out and the material deposited on one of the electrodes is weighed. 

Absolute measurements by fundamental quantities like Faraday constant and quotients of atomic and molar masses, respectively (coulom-etry, electrogravimetry, gravimetry, gas volumetry)... 

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