Cathode and Anode

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MaryBanh_2K
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Joined: Wed Sep 18, 2019 12:21 am

Cathode and Anode

Postby MaryBanh_2K » Thu Mar 05, 2020 6:34 pm

Why can we assume the cell can do work when the E value at the Cathode is bigger than the E value at the Anode?

Kevin Antony 2B
Posts: 99
Joined: Sat Sep 07, 2019 12:16 am

Re: Cathode and Anode

Postby Kevin Antony 2B » Thu Mar 05, 2020 6:40 pm

A cell can do work whenever Ecell > 0. This will always be the case if the Cathode is greater than the Anode.

Pablo 1K
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Re: Cathode and Anode

Postby Pablo 1K » Thu Mar 05, 2020 7:05 pm

Equilibrium not reached so it will continue if cathode Ecell greater than 0.

Emma Popescu 1L
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Joined: Wed Sep 11, 2019 12:16 am

Re: Cathode and Anode

Postby Emma Popescu 1L » Sat Mar 07, 2020 10:02 pm

The work done by the cell is is equal to the change in gibbs free energy. Based on the equation deltaG=-nFE, E needs to be positive so that energy is released (deltaG is negative) and thus the cell does work.

Osvaldo SanchezF -1H
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Re: Cathode and Anode

Postby Osvaldo SanchezF -1H » Sun Mar 08, 2020 3:51 am

Well for an E cell to do work its value has to positive. To find the value for cell potential it would be Ecathode - Eanode and so if cathode is larger then it will yield a positive value.

Rebekah Alfred 1J
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Re: Cathode and Anode

Postby Rebekah Alfred 1J » Sun Mar 08, 2020 9:28 am

My TA mentioned that E cell can be negative sometimes and I believe there is a question with a negative E cell in section 6N.

Jasmine Vallarta 2L
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Re: Cathode and Anode

Postby Jasmine Vallarta 2L » Sun Mar 08, 2020 10:55 am

E(cell) = E(cathode) - E(anode); since we want E(cell) > 0, E(cathode) > E(anode)

005384106
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Joined: Sat Aug 24, 2019 12:16 am

Re: Cathode and Anode

Postby 005384106 » Sun Mar 08, 2020 1:09 pm

What does the cathode and the anode do?

005384106
Posts: 101
Joined: Sat Aug 24, 2019 12:16 am

Re: Cathode and Anode

Postby 005384106 » Sun Mar 08, 2020 1:17 pm

Is the left side is the anode that dissolves, what happens to the right side (cathode)?

Kylie Lim 4G
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Re: Cathode and Anode

Postby Kylie Lim 4G » Sun Mar 08, 2020 1:54 pm

From the equation deltaG = -nFE, you can tell that a reaction is spontaneous and does work if the value of Ecell > 0. Since to find E you would subtract the potential of the cathode by the potential of the anode, you will always get Ecell > 0 if the cathode value is larger.

Vinita Saxena 2I
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Joined: Fri Aug 09, 2019 12:16 am

Re: Cathode and Anode

Postby Vinita Saxena 2I » Sun Mar 08, 2020 3:06 pm

Electrons travel from cathode to anode, so cathode>anode means work is done.

Cindy Adiwidjaja 1B
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Re: Cathode and Anode

Postby Cindy Adiwidjaja 1B » Sun Mar 08, 2020 9:57 pm

The cell will continue to do work until it dies. So E has to be positive.

Brandon Valafar
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Re: Cathode and Anode

Postby Brandon Valafar » Sun Mar 08, 2020 10:00 pm

A cell can do work when Ecell is greater than zero, meaning that the cathode must be greater than the anode.

Cindy Adiwidjaja 1B
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Joined: Sat Jul 20, 2019 12:15 am

Re: Cathode and Anode

Postby Cindy Adiwidjaja 1B » Sun Mar 08, 2020 11:24 pm

It is just standard convention that we travel from the anode to the cathode. When a cell is working spontaneously and naturally, then it will always travel from left to right.

Shail Avasthi 2C
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Joined: Fri Aug 30, 2019 12:17 am

Re: Cathode and Anode

Postby Shail Avasthi 2C » Sun Mar 08, 2020 11:31 pm

Because if there is still potential difference between the cathode and anode, then the reaction is not at equilibrium, and electrons will continue to flow from the cathode to the anode. This generates electricity.

kendal mccarthy
Posts: 109
Joined: Wed Nov 14, 2018 12:22 am

Re: Cathode and Anode

Postby kendal mccarthy » Sun Mar 08, 2020 11:36 pm

This is because the Evalue at the cathode basically determines if the Ecell will be positive or negative. When the value is positive the system can do work, when the value is negative work must be done on the system. The equation is Ecell=Ecath-Eannode, so if Ecath>Eanode, the equation will have a net positive value.

briannam_1F
Posts: 35
Joined: Wed Sep 18, 2019 12:18 am

Re: Cathode and Anode

Postby briannam_1F » Tue Mar 17, 2020 9:35 pm

We want the ECell to be positive in order to do work because once the Ecell is equal to zero then that is when the battery is considered to be "dead."


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