Determining if a cell reaction is spontaneuous

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ramiro_romero
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Determining if a cell reaction is spontaneuous

Postby ramiro_romero » Sat Feb 22, 2020 8:29 pm

For example 6L.2 and 6L.2A in the 7th edition textbook, we are asked to write a cell reaction from an electrochemical cell. After writing the reaction, we are asked to determine whether or not the reaction is spontaneous dependent upon a positive cell potential. I don't understand how to answer this part, how do we know if a reaction is spontaneous given a positive cell potential?

Brittney Hun 2C
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Re: Determining if a cell reaction is spontaneuous

Postby Brittney Hun 2C » Sat Feb 22, 2020 9:09 pm

I believe that if the reaction potential is positive then the reaction is spontaneous. They are related by deltaG = -nFE where E is the cell potential. If it is positive then delta G must be negative so it's spontaneous.

Aarja Pavade 1H
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Re: Determining if a cell reaction is spontaneuous

Postby Aarja Pavade 1H » Sat Feb 22, 2020 9:28 pm

From thermodynamics, we learned that if deltaG is negative the reaction is spontaneous. When applying this to electrochemistry and looking at the equation deltaG=-nFE, we see that a negative deltaG is acquired when E is positive. This makes sense as it was discussed in lecture that a positive voltage means a favorable (spontaneous) reaction.

Callum Guo 1H
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Re: Determining if a cell reaction is spontaneuous

Postby Callum Guo 1H » Sat Feb 22, 2020 10:36 pm

a reaction is spontaneous if gibbs free energy is negative

Lizette Noriega 1H
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Re: Determining if a cell reaction is spontaneuous

Postby Lizette Noriega 1H » Sun Feb 23, 2020 12:19 am

A positive cell potential (E) will result in a negative delta G (via the equation delta G = -nFE), thus creating a spontaneous reaction. Similarly, a negative cell potential will result in a positive delta G, creating a nonspontaneous reaction

Veronica Lu 2H
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Re: Determining if a cell reaction is spontaneuous

Postby Veronica Lu 2H » Sun Feb 23, 2020 1:08 am

a negative delta G signifies the reaction is spontaneous.


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