Standard Cell Potential

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Alex Tchekanov Dis 2k
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Joined: Sat Aug 24, 2019 12:16 am

Standard Cell Potential

Postby Alex Tchekanov Dis 2k » Sun Feb 23, 2020 4:05 pm

When you have a cell diagram and you have the Standard Cell Potential, does flipping which half-rxn is the cathode and which is the anode change the sign of the cell potential? Can you even do that? And what if you keep each as half-rxn as it is but just flip where they are in the cell diagram, how does that affect the cell potential?

Ryan_K_1K
Posts: 51
Joined: Wed Nov 14, 2018 12:18 am

Re: Standard Cell Potential

Postby Ryan_K_1K » Sun Feb 23, 2020 4:06 pm

yes, I believe flipping the reaction changes the sign of the cell potential

Anisha Chandra 1K
Posts: 118
Joined: Thu Jul 11, 2019 12:17 am

Re: Standard Cell Potential

Postby Anisha Chandra 1K » Sun Feb 23, 2020 5:37 pm

If you keep each half-reaction as it is and just flip the cell diagram, then you know:
- if the right-hand electrode in the cell diagram is the cathode, you have a positive cell potential
- if the right-hand electrode in the cell diagram is the anode, you have a negative cell potential

Prasanna Padmanabham 4I
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Joined: Thu Jul 25, 2019 12:17 am

Re: Standard Cell Potential

Postby Prasanna Padmanabham 4I » Sun Feb 23, 2020 6:01 pm

So you would just flip the signs because the reverse is occurring...

MeeraBhagat
Posts: 95
Joined: Sat Aug 24, 2019 12:15 am

Re: Standard Cell Potential

Postby MeeraBhagat » Sun Feb 23, 2020 6:32 pm

The half reactions are given as reductions, and since a reaction requires oxidation and reduction, whichever half has the oxidation occurring would have a flipped equation and sign for the cell potential. If you were to switch the sides of the diagram, then both half reactions would change signs and the reaction’s cell potential would just be the negative (or positive) version of the number you originally calculated (but cell potentials should always be positive).


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