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Question about combining equations!? Watch

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    • Thread Starter
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    Hi I have a cell diagram as shown below

    Ni(s) | Ni2+(aq) || [NO3- (aq) + 3H+ (aq)], [HNO2 (aq) + H2O (l)] | Pt

    How do I combine the two half cells to get an overall equation?

    Normally I would combine knowing:

    Oxidation equation
    Ni <-----> Ni2+ + 2e-

    Reduction equation
    NO3- + 3H+ ---> HNO2 + H2O

    However, I have no idea how to combine the two! The bottom eqn doesn't even have electrons to cancel those on the top! Or do you literally just add them?
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    Your reduction equation needs 2e- adding to the LHS
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    (Original post by Pigster)
    Your reduction equation needs 2e- adding to the LHS
    Thanks very much! Do you happen to know how I can calculate the cell emf from Ecell values for this? I am really struggling!
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    Find a data book with the two half cell values, subtract the more negative one from the more positive one.
 
 
 
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