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Electrochemical cells

  • Thread starter ana111790
  • Start date
  • #1
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Homework Statement


Based on the following chart, what ions would you use to construct an electrochemical cell with potential closest to 2.00 V?

[PLAIN]http://img546.imageshack.us/img546/5568/electrochemicalcellchar.png [Broken]

Homework Equations


I know that I am supposed to add the voltages of the 2 reactions but I am not sure how the signs would go. We are not using a textbook for this class so I have nothing to reference.


The Attempt at a Solution


I'd use the following reactions and voltages
Fe3+ -> Fe2+ (-0.771 gaining electron)
Na (s) -> Na+ (+2.71 losing electron)

so the cell voltage would be 1.94V. Is this correct?
 
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Answers and Replies

  • #2
Borek
Mentor
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Think about simple math - what is the distance between -2.7 and +0.7 points?
 
  • #3
42
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Thank you, that was very helpful!
 

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