Concentration Cell

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Jarrett Peyrefitte 2K
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Concentration Cell

Postby Jarrett Peyrefitte 2K » Wed Mar 04, 2020 5:15 pm

What is a concentration cell? How does it work? What is an example of one?

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Re: Concentration Cell

Postby KeyaV1C » Wed Mar 04, 2020 5:18 pm

A concentration cell is a cell that is has two half-cells with the same electrodes, but with different concentrations. The voltage difference is created by electron transfer from the cell with the lower concentration to the cell with the higher concentration. An example for this could be a cell where the anode consists of Zn/Zn2+(0.5M) whereas the cathode consists of Zn2+(0.02M)/Zn.

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Re: Concentration Cell

Postby EMurphy_2L » Wed Mar 04, 2020 5:19 pm

he didn't do a good job of explaining this but, from what I gathered, it's a cell/bettery which you set up to measure E by changing the concentrations of R and P. I don't have an example

Lauren Tanaka 1A
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Re: Concentration Cell

Postby Lauren Tanaka 1A » Wed Mar 04, 2020 7:14 pm

A concentration cell occurs when the anode and the cathode both have the same electrodes but with different concentrations. This would mean that the voltage difference would be created by the different concentrations rather than different cathodes.

Maya Beal Dis 1D
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Re: Concentration Cell

Postby Maya Beal Dis 1D » Wed Mar 04, 2020 7:18 pm

The standard cell potential in a concentration cell is zero because the two half cells would be identical under standard conditions.

Shail Avasthi 2C
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Re: Concentration Cell

Postby Shail Avasthi 2C » Sun Mar 08, 2020 11:37 pm

A concentration essentially uses the -(RT/nF)lnQ term of the Nernst Equation to generate (a small amount) of electricity. Since the half reactions at the cathode and anode are the same, the standard cell potential is zero. Therefore, the difference in concentration (i.e. Q) makes the overall cell potential positive.

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Re: Concentration Cell

Postby 405268063 » Sun Mar 08, 2020 11:42 pm

Like everybody else is saying, a concentration cell just happens when both the anode and cathode have the same electrodes in it but with different concentrations. The most important thing to remember for concentration cells though is that E standard cell is equal to 0.

J Medina 2I
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Re: Concentration Cell

Postby J Medina 2I » Sun Mar 08, 2020 11:47 pm

If a concentration cell has the same concentration on the anode and cathode then the reaction is at equilibrium and there is no net transfer of electrons in either direction. If this happens in a battery it means that the battery is dead.

Return to “Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)”

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