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A Reactivity Epiphany

Posted: Tue Mar 03, 2020 12:17 am
by Manav Govil 1B
This is not a question, but a mere epiphany I had while studying for the second chem test!

Does anyone remember the activity series from high school? I sure didn't until a few hours ago. For those of you who don't remember, or have never seen one, here is a link to one:

https://s2.studylib.net/store/data/0176 ... 338d0e.png

Look familiar? Well, I was doing the 6 L, M, and N problems today and was struggling to find which metal/element was being oxidized or reduced, especially when deriving an equation from a cell diagram (like Fe(s) I Fe2+(aq) II Cu(s) I Cu2+(aq)). At first, I thought of manipulating the equation so that the cell potential would be positive...but then I remembered that the cell potential may be negative under certain conditions. After taking a thorough look at the Standard Potentials, and doing question 6. 45, I realized that the elements that are better oxidation agents are located near the top of the activity series rather than the elements that are worse oxidation agents, which are located near the bottom of the activity series. I remembered that we looked at the activity series in high school to determine what got oxidized and reduced in the galvanic cell, as the elements higher up in the series got oxidized, while the ones that were comparatively lower got reduced. Therefore, we can determine that by looking at the standard potentials and comparing the oxidative capabilities of the elements, we can figure out which element gets reduced or oxidized in the problems given to us.

For example, Fe will more likely be oxidized and Cu will more likely be reduced based on the standard potentials/activity series, as the oxidation potential for Fe is 0.44 V, which is higher than the oxidation potential for Cu, which is -0.34 V. This turns out to be true.

I hope this helps anyone who is getting lost or confused in this section!

Re: A Reactivity Epiphany

Posted: Tue Mar 03, 2020 4:34 pm
by nicolely2F
We will be given a sheet with all the half-reactions and standard potentials needed, though, right?

Re: A Reactivity Epiphany

Posted: Tue Mar 03, 2020 5:13 pm
by Qiu Ya Wu 4I
nicolely2F wrote:We will be given a sheet with all the half-reactions and standard potentials needed, though, right?


Yes, those will definitely be provided!