Why doesn't potassium ion K+ from KMnO4 appear in the following two unbalanced equations: MnO4– + C2O42– Mn2+ + CO2

Question

MnO4– + Fe2+ Mn2+ + Fe3+ ?

A. KMnO4 is not added to either reaction.
B. K+ is a spectator ion and redox reactions are written as net ionic reactions.
C. The presence of K+ would result in a net positive charge in the products.
D. The equations cannot be balanced if the potassium ion K+ is present.
E. None of these.

Answer 1

K^+ is a spectator ion and that is why is isn't in the equation. The part of answer B I don't like is "and redox reactions are written as net ionic reactions." That implies that redox reactions are never written as molecular equation and that isn't true. Therefore, technically, E is the only correct answer but the spirit of the question may call for B to be the correct answer.