Module 3
1. Module 3
1.30. Page 5
Module 3—Electrochemical Reactions
Lesson Summary
In Lesson 5 you considered the following questions:
- How can a chemical system be analyzed using redox reactions?
- How is the stoichiometric method applied to redox systems?
An iron filtration system uses a strong oxidizing agent, permanganate ions, to oxidize iron(II) ions into a form that allows them to be filtered and removed from drinking water. The selection of permanganate as a reactant not only assures a spontaneous and stoichiometric reaction but also allows for assessment of the system's operation.
Similar principles are applied in the design of a redox titration in which spontaneous and stoichiometric reactions are used to perform quantitative analysis. Some oxidizing agents have distinctive colours, like permanganate and dichromate. As these substances undergo electrochemical change, their colour change or lack of change can provide a detectable endpoint for titrations, allowing for accurate quantitative analysis.