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# Electrolysis - Chemistry, help needed. watch

1. 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)'
2. Is this for double science? Eeeeek

Is the answer 0.15g? Or am I talking rubbish?
3. I need to know how to work it out because I have no idea, can anybody help?
4. What is the answer though? And again, is this for double or triple award science, because I haven't really learnt about that?
5. 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).
6. 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.
7. (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...
8. it may be right, thanks for trying.
9. 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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Updated: June 13, 2006
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