Theory of Redox Titrations

To follow the course of the reaction, we use a Pt indicator electrode and a calomel (or other) reference electrode. At the Pt indicator electrode, two reactions each come to equilibrium  

The titration reaction goes to completion after each addition of titrant. The equilibrium constant is given by Equation 14-23 K = at 

Strong acid prevents hydrolysis reactions such as Fe + H2O Fe(OH) -F H . 

The potentials cited here are formal potentials that apply in 1 M HCIO4. 

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This chapter introduces the theory of redox titrations and discusses some common reagents. A few of the oxidants and reductants in Table 16-1 can be used as titrants.2 Most reductants react with 02 and require protection from air to be used as titrants. 

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