ATAR Notes: Forum
Archived Discussion => Written Examinations => 2008 => End-of-year exams => Exam Discussion => Victoria => Chemistry => Topic started by: Mao on November 13, 2008, 01:27:02 pm
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In a fuel cell, where the net flow of H+ is to the right, and the flow of electrons in the external circuit is also to the right [anode on the left, cathode on the right], which way does the anion electrolyte flow... if at all?
to fellow 2008 ex-chem students [win!], question 8, b.
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Oh crap, now that you mention this question, I think I actually skipped it altogether and forgot to go back and do it since you had to draw on the actual diagram o_O Uh oh.
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yeh i pointed it towards the cathode assuming that the negatively charged h2po4 was going to the be attracted to the +
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Anions flow to the anode, to replace the loss of negative charge. (Like in a salt bridge)
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I also assumed H2PO4- flow would oppose the electron flow, hence right-to-left on the diagram.
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thanks coblin
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WAIT
there is no electrostatic build-up of charges at the anode though... as the products (H+ from H2) are continuously migrating towards the cathode... doesn't that do the same thing as anions migrating towards the anode?
there is a limited amount of anode, if it does indeed move towards the anode, wouldn't the fuel cell eventually "go flat" when the electrolyte is depleted?
I have a feeling that they don't move at all.
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Anions flow to the anode, to replace the loss of negative charge. (Like in a salt bridge)
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