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Homework Help: Temperature's affect on Galvanic

  1. Mar 31, 2010 #1
    1. The problem statement, all variables and given/known data
    Determine the affect of temperature on voltage on an electrochemical cell in standard 1 M solutions.


    2. Relevant equations

    Only equation in high school chem: Ne=It/F

    This Nernst equation keeps on coming up even though we haven't learned it in class.

    Ecell=E°cell- (RT/nF) lnQ.


    3. The attempt at a solution

    Our high school class did 6 experiments and we came up with the conclusion that the voltage increases .012 V/k. The High school lab conditions weren't ideal and I don't really trust the results.I'm all confused now.

    Pratically, as temperature increases the reaction rate should increases. This is why car batteries have trouble starting in winter and people keep batteries in the fridge.

    Theoretically, as temperature increase, the voltage should drop based upon Nernst. The non-sportaneous reaction of the cathode oxidizing will happen more readily and counteract the oxidation of the anode.

    Help is much appreciated.
     
    Last edited: Mar 31, 2010
  2. jcsd
  3. Apr 1, 2010 #2
    Under what conditions is lnQ positive, and under what conditions is it negative?
     
  4. Apr 1, 2010 #3
    Ahh I got it. Seems like the aluminum solution was off in class and that's why it has the biggest rate of change.
     
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