18. Which of the following is the STRONGEST reducing agent?
A. MnO(s)
B. Mg2+(aq)
C. Cl-(aq)
D. Zn(s)
explanation
The best reducing agent is the compound that is most favorably oxidized. According to the table, Mg2+(aq) is an oxidizing agent, because it has no electrons to lose and can gain two electrons to form the neutral metal. This eliminates choice B. According to the chart, it is unfavorable to oxidize Cl-(aq) or MnO(s) (both have negative voltages for oxidation), so choices A and C are eliminated. The oxidation potential for Zn(s) is +0.76 V, making it the strongest reducing agent of the four answer choices.
i understand the concept but i don't get how magnesium is no the answer. is there an easy way to do problems like this?
A. MnO(s)
B. Mg2+(aq)
C. Cl-(aq)
D. Zn(s)
explanation
The best reducing agent is the compound that is most favorably oxidized. According to the table, Mg2+(aq) is an oxidizing agent, because it has no electrons to lose and can gain two electrons to form the neutral metal. This eliminates choice B. According to the chart, it is unfavorable to oxidize Cl-(aq) or MnO(s) (both have negative voltages for oxidation), so choices A and C are eliminated. The oxidation potential for Zn(s) is +0.76 V, making it the strongest reducing agent of the four answer choices.
i understand the concept but i don't get how magnesium is no the answer. is there an easy way to do problems like this?