## Concentration Cells

$E_{cell} = E_{cell}^{\circ}-\frac{RT}{nF}\ln Q$

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### Concentration Cells

Can someone explain to me how a concentration cell works if it is using the same molecule? As in, where do the electrons come from and go if only one molecule is there for redox reactions

SnehinRajkumar1L
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### Re: Concentration Cells

Based on concentration, one side acts as the anode and the other as the cathode. Thus, one of them is reduced and the other is oxidized, depending on which has a higher concentration and produces a current.

Emma Popescu 1L
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### Re: Concentration Cells

The standard E cell potential will be 0. However, current is driven by the difference in concentration of the ions, which move from a higher concentration to a lower concentration.

Sara Richmond 2K
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### Re: Concentration Cells

Does the cell flow from anode to cathode or cathode to anode? which has the higher concentration anode or cathode?

Ian Morris 3C
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### Re: Concentration Cells

Sara Richmond 2K wrote:Does the cell flow from anode to cathode or cathode to anode? which has the higher concentration anode or cathode?

electrons always flow from anode to cathode

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Joined: Fri Aug 02, 2019 12:16 am

### Re: Concentration Cells

If you have different concentrations of the same species in the sides of the cell, then in the Nernst equation, Eo is zero but lnQ is nonzero. Eo is zero because there is no difference in reduction potential (same species). Since you have more reactants than products (difference in concentration), lnQ is nonzero and therefore the E of the cell is some positive number. Q would be the same species on both the numerator and denominator, but since the concentrations are different, the cell works.

205291012
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### Re: Concentration Cells

in a concentration cell, the standard potential energy is 0 and the potential energy is very low voltage. the whole reaction is driven entirely by a change in concentration gradient. thus the reaction proceeds because there is a tendency to move from high concentration to low concentration

Kylie Lim 4G
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### Re: Concentration Cells

In a concentration cell, the reaction is driven by a difference in concentration, with electrons flowing from the anode (which should be at a lower concentration) to the cathode (which should be at a higher concentration). The voltage is created as the two concentrations move towards equilibrium.

CNourian2H
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Joined: Fri Aug 30, 2019 12:16 am

### Re: Concentration Cells

Basically, the electrons flow through the different concentrations, where it goes from a higher to a lower concentration. The lower concentration will always be for your product.

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