Spontaneous Directions  [ENDORSED]

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Abigail Volk 1F
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Spontaneous Directions

Postby Abigail Volk 1F » Thu Feb 22, 2018 10:21 pm

How do you predict the spontaneous direction of a redox reaction using standard reduction potentials.

David Minasyan 1C
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Re: Spontaneous Directions

Postby David Minasyan 1C » Thu Feb 22, 2018 10:27 pm

If the standard potential is positive (it'll make delta G negative bc of delta G = -nFE) so it'll be spontaneous.

Guangyu Li 2J
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Re: Spontaneous Directions

Postby Guangyu Li 2J » Fri Feb 23, 2018 12:27 pm

The values of standard potential can help us determine whether the process is spontaneous. When Eo is >0 the process is spontaneous and tend to produce products while when Eo <0 the process is not spontaneous and tend to produce the reactants.

The example of 14.5 can help you better understand this point.

Hope this helps!

Meredith Steinberg 2E
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Re: Spontaneous Directions

Postby Meredith Steinberg 2E » Fri Feb 23, 2018 1:00 pm

Redox reactions are spontaneous when standard potential is positive. This makes sense if you think about the equation G=-nFE. If E is positive, G will be negative, indicating a spontaneous process.

204918982
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Re: Spontaneous Directions

Postby 204918982 » Fri Feb 23, 2018 2:27 pm

standard potential has to be positive for the reaction to be spontaneous

Ivy Lu 1C
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Re: Spontaneous Directions

Postby Ivy Lu 1C » Fri Feb 23, 2018 2:31 pm

You want the standard potential of the reaction to be positive because that would make deltaG be negative (deltaG=-nFE) and k be greater than 1.

Rachel Lu_dis1H
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Re: Spontaneous Directions

Postby Rachel Lu_dis1H » Fri Feb 23, 2018 4:54 pm

Because of the equation deltaG= -nFE, E (standard reduction potential) must be positive in order for the reaction to be spontaneous. When E is positive, deltaG is negative (when deltaG is negative the reaction is spontaneous).

Tatiana Hage 2E
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Re: Spontaneous Directions  [ENDORSED]

Postby Tatiana Hage 2E » Fri Feb 23, 2018 7:32 pm

If the standard potential is positive, ∆G is negative and the reaction has a spontaneous tendency to form products.
If the standard potential is negative, ∆G is positive and the reverse of the cell reaction is spontaneous, so the cell reaction has a spontaneous tendency to form reactants.


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