1. The problem statement, all variables and given/known data The problem asks me for the reduction potential of two metals: Zn/Zn2+ and Cu/Cu2+ All I need to know is how do I determine which one will be reduced and which one will be oxidized. The answer to the question puts the Zinc half reaction as Zn → Zn2+ + 2e- And of course the Copper half reaction is put the opposite way so that it's reduced. But they never tell me how they know which way to arrange the equations. Like why didn't they make the copper half reaction go Cu → Cu2+ + 2e- so that it is oxidized? I know how to answer the rest of the question, I just can't find anywhere in the text that tells me this vital detail. Thanks.