posted by Anonymous .
Balancing redox equations
reactants: Cu, NO3^- (the negative sign is nex to the O, above the 3).
products: Cu^2+, NO2
Cu+ NO3^- ----> Cu^2+ + NO2
Okay, I don't understand how to do this problem...but something someone needs to clear up for me...why does N in NO3^- have an oxidation state of 5 and in then NO2 has an oxidation state of 4?