Revising first year Organic Chemistry help???

Posted on 2015-12-01 06:41:00 in Chemistry by SHAUN

I have been given the example of -
I2(s) + 5Cu+(aq) +6H2O -> 2IO3-(aq) + 5Cu(s) + 12H+(aq)

I ve broken it down into the two Reduction Half-Reactions -
Cu2+(aq) + 2e- -> Cu(s)
2IO3-(aq) +12H+(aq) + 10e- -> I2(s) + 6H2O(l)

According to the Standard Reduction Potentials given in Chemistry: The Central Science 13th edition, these half reactions are worth -
+0.337V
+1.195V

I take the formula -
Ecell = Ered(cat) - Ered(an)
Substitute in the values, knowing that the most positive value is attributed to the cathode and the most negative value is attributed to the anode. This gives me
Ecell = 1.195V - 0.337V

However. The textbook then tells me that this reaction is NOT spontaneous and the only way I can figure to make that happen is if the 1.195V is the oxidation reaction and is thus a negative number (and is also then not the most positive value).

Any help would be greatly appreciated

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