Why doesn't potassium ion K+ from KMnO4 appear in the following two unbalanced equations: MnO4– + C2O42– Mn2+ + CO2
MnO4– + Fe2+ Mn2+ + Fe3+ ?
A. KMnO4 is not added to either reaction.
B. The presence of K+ would result in a net positive charge in the products.
C. K+ is a spectator ion and redox reactions are written as net ionic reactions.
D. The equations cannot be balanced if the potassium ion K+ is present.
E. None of these.
You REALLY should use arrows. How are we to know which are the reactants and which the products? I know which is which in this case, I think, so here goes.
K^+ is a spectator ion.
C. K+ is a spectator ion and redox reactions are written as net ionic reactions.
To determine the correct answer, let's analyze each option and eliminate the incorrect ones.
Option A states that KMnO4 is not added to either reaction. To verify this, we can check the reactants of each equation. In both equations, KMnO4 is not mentioned as a reactant, so option A is a plausible answer.
Option B suggests that the presence of K+ would result in a net positive charge in the products. To assess this, we can check the charges of the products in the given equations. In both cases, the products have both positive and negative charges, proving that the presence of K+ would not necessarily create a net positive charge. Therefore, option B is incorrect.
Option C proposes that K+ is a spectator ion, and redox reactions are written as net ionic reactions. To evaluate this claim, we need to consider if K+ ions play an active role in the reaction or if they remain unchanged throughout the process. K+ ions do not participate in the redox reactions; they remain as spectator ions, meaning they do not undergo any changes. Therefore, option C is a valid answer.
Option D claims that the equations cannot be balanced if the potassium ion K+ is present. To test this statement, we can review the given equations and see if adding K+ would prevent them from being balanced. However, the presence of K+ would not affect the balancing of the equations. Thus, option D is incorrect.
By the process of elimination, we can conclude that the correct answer is C. K+ is a spectator ion, and redox reactions are written as net ionic reactions.