Relationship between work, cell potential, and delta G

$\Delta G^{\circ} = -nFE_{cell}^{\circ}$

claudia_1h
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Relationship between work, cell potential, and delta G

Can someone please explain (conceptually, not with equations) the relationship between work, cell potential, and delta G? Like explain why wmax is = to delta G.

Diana A 2L
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Re: Relationship between work, cell potential, and delta G

claudia_1h wrote:Can someone please explain (conceptually, not with equations) the relationship between work, cell potential, and delta G? Like explain why wmax is = to delta G.

So when delta G is negative, this implies spontaneity (a reaction natural wants to occur in that direction). This means that the reaction will release free energy because since its spontaneous it doesn’t take much for the reaction to occur since its inclined to happen. Free energy (Gibbs free energy) can be used to do electrical work, so the most work that can be done correlates to the negative delta G value. This is why wmax=delta G. Now, imagine the battery of an iPhone. Cell potential of a battery is like how much charge it has. A high positive cell potential means the battery is at 100% for example, meaning you can do lots of hours of chemistry work on chemistry community before your phone dies. A high cell potential is correlated to a high delta G value, because with a lot of free energy, you can do a lot of chemistry work. There we go:)

Joowon Seo 3A
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Re: Relationship between work, cell potential, and delta G

When delta G is negative, there is energy free to do work. Cell potential wants to go down. IF cell potential goes down there is a release of energy free to do work.

Diana A 2L
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Re: Relationship between work, cell potential, and delta G

Joowon Seo 3A wrote:When delta G is negative, there is energy free to do work. Cell potential wants to go down. IF cell potential goes down there is a release of energy free to do work.

I don’t think this is a correct. In the equation delta G= -nFEcell, if cell potential is higher, and more positive, then Gibbs free energy will be a larger negative, meaning a reaction will be spontaneous, with a larger release of energy free to do work.

CNourian2H
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Joined: Fri Aug 30, 2019 12:16 am

Re: Relationship between work, cell potential, and delta G

Diana A 2L wrote:
Joowon Seo 3A wrote:When delta G is negative, there is energy free to do work. Cell potential wants to go down. IF cell potential goes down there is a release of energy free to do work.

I don’t think this is a correct. In the equation delta G= -nFEcell, if cell potential is higher, and more positive, then Gibbs free energy will be a larger negative, meaning a reaction will be spontaneous, with a larger release of energy free to do work.

Ya I think you are right. a higher cell potential in this case would mean gibbs free emergy is more neg and therefore more spontaneous.

Indy Bui 1l
Posts: 99
Joined: Sat Sep 07, 2019 12:19 am

Re: Relationship between work, cell potential, and delta G

Diana A 2L wrote:
Joowon Seo 3A wrote:When delta G is negative, there is energy free to do work. Cell potential wants to go down. IF cell potential goes down there is a release of energy free to do work.

I don’t think this is a correct. In the equation delta G= -nFEcell, if cell potential is higher, and more positive, then Gibbs free energy will be a larger negative, meaning a reaction will be spontaneous, with a larger release of energy free to do work.

This is right and it makes sense conceptually. A larger positive Ecell value would make a larger negative delta G, meaning it is more spontaneous.

Diana A 2L
Posts: 106
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Re: Relationship between work, cell potential, and delta G

Yes! Glad I got the concept. Thank you guys^^

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