ATAR Notes: Forum
HSC Stuff => HSC Science Stuff => HSC Subjects + Help => HSC Chemistry => Topic started by: latifa on October 06, 2011, 11:05:28 am
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its driving me crazy, just weni think ive got it, i do a lil mistake that stuffs up the whole answer 4 me. the sad thing is wen i look at the solutions, its so simple!!!! i feel lyk ripping my chem books apart!!!! im getting frustrated >:(, its just electrolysis, everything else is fine.
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What kind of mistakes are you making?
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simple mistakes, like instead of multiplying by F constant i would divide, or at times id see a diff q n i wont kno how to approach it, then wen i c da solutions its so simple!. dunno wat to do, cuz im killin every section, n i dnt want electrolysis to put me down.
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Well with electrolysis i think the best thing to do is look at what information they give you and think about which formulas they relate to. Dont give up!
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yh ur right. thnx . :)
dw i'll try not 2 give up.
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With electrolysis, how do we find the potential needed? Is there a generic Ecathode - Eanode formula ?
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Please make your own thread next time if you can.
As for your question, Electrode potential of a cell = Standard Electrode potential (the one in the table) - RT/nF * ln K
Search "Nernst equation"
n is the number of electrons transferred per mole of reaction, so if I had Sn 2+ + F2 => 2F - + Sn 4+, then n = 2 as two electrons are transferred for every Sn 2+ ion there is, or every unit of reaction if that makes sense.
F is a Faraday, or 96485 C/mol which is the charge on a mole of electrons.
K is your equilibrium constant
So given the conditions, you could then work out the electrode potential of this cell based on the concentrations of each reactant and the standard electrode potentials.