Prelab Questions.

Questions you NEED to answer in a written form in your notebook before the Lab. 

Analyze the graph below answer the following questions:

• What electrochemical reactions take place on the top part of the CV curve and the bottom part?
• Label the anodic and the cathodic currents
• Is the redox reaction reversible or irreversible in this case?
• What can you say about the rates of oxidation and reduction reactions (large, small)?
• What are i_pc and i_pa? Based on that and the equation (5), what is the concentation of K₃Fe(CN)₆? Presume that the electrode area is A = 0.1 cm²
• What is E_1/2 for Fe(CN)₆^3-?
• Sketch the CV for K₄Fe(CN)₆
• What oxidation states do you expect for Ru?

What kind of questions you MAY be asked before the Lab.

• Does E_1/2 depend on temperature? solvent? electrolyte?anything else?
• Why does the CV amplitude depend on the sweep rate?
• Why do we need electrolyte in the cell?
• How would the picture above change if one of the redox reactions (reduction or oxidation) becomes slow?
• Why do you need to blow inert gas through the cell?
• Why polishing of electrodes is necessary? What does it do?

Last updated 02/01/02.