cyentist
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Is it possible to generate electricity from a pH gradient?
Is it possible to generate electricity from a pH gradient?
Thanks!
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Steam
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Well technically all pH probes run by measuring a voltage potential across a standard electronde but I think you are asking something a bit more
profound. Can a large gradient in hydrogen ion activity drive create a potential.
Try this on for size: electro-osmosis.
https://www.youtube.com/watch?v=zzVa_tX1OiI
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Sulaiman
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Yes, if aqueous redox is involved.
Electrode potentials are a direct function of pH.
(approximately 59mV per unit of pH difference)
CAUTION : Hobby Chemist, not Professional or even Amateur
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cyentist
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Quote: Originally posted by Sulaiman  |
Yes, if aqueous redox is involved.
Electrode potentials are a direct function of pH.
(approximately 59mV per unit of pH difference) |
You mean I need to have a material that will be oxidised and another material that will be reduced?
Isn't it possible to generate electricity from two solutions of HCl with different concentration just by connecting them with a wire?
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Carbon8
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As you mention, you might be able to generate electricity from a concentration cell with an acid (or base) having two different concentrations in the
two arms of the cell, but a better example would be a "neutralization cell."
Here are two recent (but gated) examples:
Acid–base machines: electrical work from neutralization reactions
https://pubs.rsc.org/en/content/articlelanding/2017/cp/c7cp0...
Reverse Electrodialysis Chemical Cell for Energy Harvesting from Controlled Acid–Base Neutralization
https://pubs.acs.org/doi/10.1021/acs.est.8b06361
I have also attached a description of a simple neutralization cell.
Attachment: electricity from neutralization.pdf (1.3MB)
This file has been downloaded 282 times
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Sulaiman
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| Quote: Originally posted by cyentist | | Quote: Originally posted by Sulaiman |
Yes, if aqueous redox is involved.
Electrode potentials are a direct function of pH.
(approximately 59mV per unit of pH difference) |
You mean I need to have a material that will be oxidised and another material that will be reduced?
Isn't it possible to generate electricity from two solutions of HCl with different concentration just by connecting them with a wire?
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In this case it is the acid/base/water that take part in the redox,
not the metal, which is just a collector or source of electrons.
That's why I said it should be an aqueous environment.
CAUTION : Hobby Chemist, not Professional or even Amateur
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Tsjerk
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If you have a semi-permeable membrane it is easy. Bacteria and mitochondria reach 180 mV over their membranes all the time.
They actually use it to transform energy from metabolism (ATPases) to other needs (import/export solubles).
https://en.wikipedia.org/wiki/Membrane_potential
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cyentist
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Thanks, how can I calculate the voltage generated from a specific pH gradient?
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Tsjerk
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Look for the Nernst equation. It is how pH meters work.
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cyentist
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This converts pH to voltage: https://www.traditionaloven.com/conversions_of_measures/ph-v...
However, even the maximum pH difference of 14, gives only 400mV.
Can anyone explain please?
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phlogiston
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Probably not quite what you were after with your question, but interesting to mentioning in this context: a pH gradient lies at the heart of energy
'production' that takes place in the mitochondria of eukaryotic cells. Fuels are burned to pump protons across the inner fosfolipid membrane of
mitochondria, establishing a pH gradient as an intermediate store of energy. Subsequently, the flow of protons back across the membrane drives the
production of an energetic molecule (ATP) that is utilised to power many biological processes, including the contraction of muscles.
So, the electrical energy provided to the light on your bicycle, powered by the dynamo attached to your bicycle wheel, once existed as a pH gradient
across the inner membrane of the mitochondria in your muscles.
Therefore, 'yes', it is possible.
[Edited on 30-8-2019 by phlogiston]
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"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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VSEPR_VOID
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It exists in the body of every organism with mitochondria
Molecules are broken down to basiclly accumulate a gradient of protons which are used to power proteins by that osmonic pressure I think
https://en.wikipedia.org/wiki/Proton_pump
Within cells interlinked
Within cells interlinked
Within cells interlinked
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