2000Q Book: General Chemistry #1344

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avo
Posts: 36
Joined: Wed Jun 12, 2019 6:01 pm

2000Q Book: General Chemistry #1344

Post by avo » Wed Jul 03, 2019 12:04 am

Hi guys, I'm having trouble understanding the logic behind the right answer here. To my understanding, oxidizing and reducing reagents want to be reduced and oxidized, respectively. If the table listed gives standard reduction potentials, I would've thought the oxidizing/reducing reagents should've been the most positive and most negative values, respectively. Since we're localized to Na and Cl, I would've assumed that meant Na (s) / Cl- OR Cl2 and Na+ but neither of those answer choices appear so I'm a bit lost!
NS_Tutor_Will
Posts: 766
Joined: Fri May 25, 2018 9:15 am

Re: 2000Q Book: General Chemistry #1344

Post by NS_Tutor_Will » Wed Jul 03, 2019 8:19 am

Thanks for the question!

So this table is showing the standard reduction potentials (i.e. how badly does each compound want to be reduced). Whichever compound has the highest reduction potential will also, by definition, be the best oxidizing agent, since a compound being reduced means it is oxidizing another compound. So, the most positive E° for reduction potential will correspond with the best oxidizing agent. The most negative E° for reduction potential will correspond with the best reducing agent (and, if we looked at E° for oxidation potential, it would be the most positive). Remember, these are reverse processes. So if we flip the sodium half reaction, we'll have a positive value for the oxidation of solid sodium. Therefore, the best oxidizing agent is Cl2 (gas) with a reduction potential of 1.36 V and the best reducing agent is Na (solid).

I hope this is helpful!
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