Test 2, Question #5

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Hena Sihota 1L
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Joined: Fri Sep 29, 2017 7:07 am
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Test 2, Question #5

Postby Hena Sihota 1L » Sat Mar 10, 2018 12:33 am

This problems asks you to rank the following in order of increasing reducing power:
a)Zn, Mn, Cr
b)I2, Br2, Al
I understood that the more negative the reduction potential, the greater the reducing power, and applied this logic to both parts.
I wrote out the reduction potentials and ordered them from least negative reduction potential to most negative reduction potential.
a) Zn:-0.76, Mn:-1.18, Cr:-0.74 Cr<Zn<Mn
b)I2:0.54, Br2:1.07, Al:-1.66 Br2<I2<Al
I got part (b) correct, but I got part (a) wrong. What did I do wrong?

Ammar Amjad 1L
Posts: 54
Joined: Thu Jul 27, 2017 3:00 am
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Re: Test 2, Question #5

Postby Ammar Amjad 1L » Sat Mar 10, 2018 11:47 am

Hey, so the potential you've written for Cr should be -0.91 V, the one you've written is the potential for Cr^3+ going to Cr, you need to use the potential from Cr^2+ to Cr. Hope this helps.
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