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If you use the second method Lavelle spoke about in class to calculate the standard reduction potential of the cell, you first identify the half reactions and look up the standard reduction potentials of these respective half reactions. Thus, I believe, in the tables, you'll notice that the half reactions are written as reduction reactions because the values for the reduction potentials are given. However, when you proceed to balance the half reactions and write out the cell reaction, you'll eventually flip one of the reactions (the one that is supposed to be an oxidation) so it becomes an oxidation reaction and just negate the given standard reduction potential before summing the two equations together.
All the half reactions are written as reductions for the sake of consistency; they could just as easily be all written as oxidation reactions (and I think some tables have it like that). When writing the half reactions you should write it with one reduction and one oxidation half reaction, and for the reaction you flip, you need to flip the sign of the potential.
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