Interpretation and application of transport numbers

In section 4.5.1 it was pointed out how necessary it is to know and understand the electrode process which occurs at the anode and cathode during 

Indicator electrolyte solution cation formed by dissolution J/of anode 

The above observations are easily explained when the nature of the ions present in more concentrated solutions of cadmium iodide is understood. In such solutions this electrolyte exists largely as Cd , and Cdl4 , i.e. as the simple cadmium ion with a double charge and as a doubly charged anionic complex ion. This latter will obviously migrate in a direction opposite to 

A more fundamental use of transport numbers is in the determination of ion conductances from measurements of conductances of electrolytes an ion conductance being a fraction t of the observed value for the electrolyte. In order to obtain infinite dilution values of ion conductances, equivalent conductances and transport numbers also have to be obtained by extrapolation to these conditions. In some cases this process may be unreliable. Once, however, the conductance of a given ion is reliably obtained, it is possible to obtain those of any oppositely charged partner in a variety of electrolytes by subtraction. 

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