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    Im finding the quantative electrolysis questions hard, could somebody tell me how to answer this:

    'This is the equation at the cathode when sodium chloride solution is electrolysed -

    2H+ + 2e- -------> H2

    What mass of hydrogen is given off when a current of 2 amp flows for 1 hour?(One mole of hydrogen atoms is produced from 96000 coulombs of electricity)'
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    Is this for double science? Eeeeek

    Is the answer 0.15g? Or am I talking rubbish?
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    I need to know how to work it out because I have no idea, can anybody help?
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    What is the answer though? And again, is this for double or triple award science, because I haven't really learnt about that?
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    for single science higher, If you havnt dont it dont worry, I dunno what the answer is I havnt got the mark scheme. (triple award).
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    Hmm I do triple award (higher) as well! This is worrying! Which exam board do you take? I really have no idea with this question though, sorry. If it's Edexcel then I have the mark schemes for a couple of papers, but it doesn't look like anything I've ever come across before.
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    (Original post by john..........)
    Im finding the quantative electrolysis questions hard, could somebody tell me how to answer this:

    'This is the equation at the cathode when sodium chloride solution is electrolysed -

    2H+ + 2e- -------> H2

    What mass of hydrogen is given off when a current of 2 amp flows for 1 hour?(One mole of hydrogen atoms is produced from 96000 coulombs of electricity)'
    OK, this is probably wrong, but I'm going to give it a shot

    Charge = Current x time = 2 x (60 x 60) = 7200 C

    If 1 mole of hydrogen atoms is produced from 96000 C, then 7200/96000 moles of hydrogen atoms are produced from 7200 C

    RMM H2 = 2

    mass of H2 = (7200/96000) x 2 = 0.15 g

    Does this make any sense? I don't think it's right, cause I totally disregarded the ionic equation...
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    it may be right, thanks for trying.
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    I just realised that I used 9600 C instead of 96000. It's edited, and now I've got the same answer as Excalibur got originally, so maybe it's right?
 
 
 

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