Coulometric titration external generation

Method for the external generation of oxidizing and reducing agents in coulometric titrations. 

The result of the entire procedure, being a 100% conversion of Fe(II) to Fe(III), thus represents a so-called coulometric titration with internal generation of course, it seems possible to titrate Fe(II) with Ce(IV) generated externally from Ce(III), but in this way one would unnecessarily remove the solution of the 100% conversion problem hence the above titration with internal generation in the presence of a redox buffer as an intermediary oxidant represents an extremely reliable method, unless occasional circumstances are prohibitive for the remainder internal generation offers the advantage of no dilution of the analyte solution. 

Figure 4.5. Apparatus for the external generation of titrant for coulometric titrations.

Figure 3. Cell for coulometric titration with external generation of reagent. (Reproduced from Ref. 28.

If the oxidation or reduction of H2O is carried out externally using the generator cell shown in Figure 11.25, then H3O+ or OH can be dispensed selectively into a solution containing a basic or acidic analyte. The resulting reaction is identical to that in an acid-base titration. Coulometric acid-base titrations have been used for... 

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