## Spontaneity

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

905373636
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Joined: Thu Aug 01, 2019 12:15 am

### Spontaneity

Do higher cell potentials within a cell indicate anything about the rate of the reaction or just the spontaneity?

Ronak Naik
Posts: 103
Joined: Sat Jul 20, 2019 12:15 am

### Re: Spontaneity

Higher cell potentials will indicate a greater level of spontaneity; however, spontaneity is a thermodynamic concept. It does not relate to kinetics, and thus, will not tell us anything about the speed of a reaction.

Chris Tai 1B
Posts: 102
Joined: Sat Aug 24, 2019 12:16 am

### Re: Spontaneity

Spontaneous processes don't necessarily happen quickly, it just means that over time there is a tendency for that reaction to occur.
The equation that relates spontaneity to the cell potential difference is deltaGknot = -nFEknot. This makes sense, because the more positive the E value of cell potential is, the battery is able to convert more energy to do electrical/chemical work, and because there is a negative sign, the value of deltaGknot will be more negative. Hence, the reaction as a whole will be more negative, and have a spontaneous nature. The opposite is true if the value of E is negative.

DHavo_1E
Posts: 118
Joined: Sat Aug 17, 2019 12:17 am

### Re: Spontaneity

Chris Tai 1B wrote:Spontaneous processes don't necessarily happen quickly, it just means that over time there is a tendency for that reaction to occur.
The equation that relates spontaneity to the cell potential difference is deltaGknot = -nFEknot. This makes sense, because the more positive the E value of cell potential is, the battery is able to convert more energy to do electrical/chemical work, and because there is a negative sign, the value of deltaGknot will be more negative. Hence, the reaction as a whole will be more negative, and have a spontaneous nature. The opposite is true if the value of E is negative.

Hello,

What does it mean when E is positive or negative? Thank you!

Angela Wu-2H
Posts: 50
Joined: Fri Aug 30, 2019 12:16 am

### Re: Spontaneity

Ronak Naik wrote:Higher cell potentials will indicate a greater level of spontaneity; however, spontaneity is a thermodynamic concept. It does not relate to kinetics, and thus, will not tell us anything about the speed of a reaction.

So then what tells us about the speed of a reaction? Is it just a catalyst?

305385703
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Joined: Thu Jul 11, 2019 12:15 am

### Re: Spontaneity

Cell potential has nothing to do with reaction speed, although there are other factors that can speed up a reaction with a large cell potential. Think of it as the distance in energy between the products and reactants.

VLi_2B
Posts: 99
Joined: Sat Sep 14, 2019 12:15 am

### Re: Spontaneity

DHavo_1E wrote:
Chris Tai 1B wrote:Spontaneous processes don't necessarily happen quickly, it just means that over time there is a tendency for that reaction to occur.
The equation that relates spontaneity to the cell potential difference is deltaGknot = -nFEknot. This makes sense, because the more positive the E value of cell potential is, the battery is able to convert more energy to do electrical/chemical work, and because there is a negative sign, the value of deltaGknot will be more negative. Hence, the reaction as a whole will be more negative, and have a spontaneous nature. The opposite is true if the value of E is negative.

Hello,

What does it mean when E is positive or negative? Thank you!

If an electrode potential is negative that means it's donating electrons. If the electrode potential is positive it means that it is taking electrons.

Chris Tai 1B
Posts: 102
Joined: Sat Aug 24, 2019 12:16 am

### Re: Spontaneity

DHavo_1E wrote:
Chris Tai 1B wrote:Spontaneous processes don't necessarily happen quickly, it just means that over time there is a tendency for that reaction to occur.
The equation that relates spontaneity to the cell potential difference is deltaGknot = -nFEknot. This makes sense, because the more positive the E value of cell potential is, the battery is able to convert more energy to do electrical/chemical work, and because there is a negative sign, the value of deltaGknot will be more negative. Hence, the reaction as a whole will be more negative, and have a spontaneous nature. The opposite is true if the value of E is negative.

Hello,

What does it mean when E is positive or negative? Thank you!

If E is a positive value, then there is a positive difference in cell potential, which means there's potential for the cell to do work. This phenomenon is favorable, and indicates that it is likey that electrons will flow in a redox reaction. If E is a negative value, then the opposite is true.