Understanding Three Electrode System Interactions

[tirrel]

Hello, I have two doubts.
In a three electrode system, do the reference electrode and the auxiliary electrode interact (by direct contact or other way) with the analyte? And why?
The second doubt consists in this point and I think is connected to half of the previous question: during for example a voltammetry experiment does the analyte get charged? Told another way, the reactions happening at the working electrode are balanced by a counter reaction happening at the auxiliary electrode involving the analyte? (this is why I asked if the auxiliary electrode has physical contact with the analyte)

Thanks a lot,

tirrel

 

[_coyote_]

The reference and the auxiliary electrodes in a three electrode system do not interact with the analyte directly. The reference electrode is used to provide a stable potential to the system - it is a measure of the potential of the working electrode relative to the reference electrode. The auxiliary electrode is used to complete the electrical circuit and is typically a counter electrode, which is made of a different material than the working electrode. It is this counter electrode that is involved in the oxidation or reduction reactions that occur during voltammetry experiments. The analyte is charged during these experiments as the oxidation or reduction reactions involve the transfer of electrons from the counter electrode to the analyte.