Mistake in the exam! (1 Viewer)

[nichorowitz]

Anyone else pick up the mistake?
In the galvanic cell where you had to calculate cell potential the electrolytes weren't 1.0 mol/L therefore the standard potential table had the wrong values and it was impossible to correctly calculate the cell potential.

 

[CalumGemmell]

Anyone else pick up the mistake?
In the galvanic cell where you had to calculate cell potential the electrolytes weren't 1.0 mol/L therefore the standard potential table had the wrong values and it was impossible to correctly calculate the cell potential.

I don't think the concentration has anything to do with the values for the standard reduction potentials.

 

[mirakon]

Anyone else pick up the mistake?
In the galvanic cell where you had to calculate cell potential the electrolytes weren't 1.0 mol/L therefore the standard potential table had the wrong values and it was impossible to correctly calculate the cell potential.

i don't think this matters tbh

 

[PaterzAttack]

I don't think the concentration has anything to do with the values for the standard reduction potentials.

i don't think this matters tbh

looks like you're fucked if you relied on this "mistake"

 

[frankcat1]

Actually I think it does matter from what I've read
"The cell potential is a useful value when it can be compared to other cell potentials obtained under the same standard set of conditions—that is, when all participating gases exist at a pressure of 1 atm, and all ions are present in a concentration of 1 mol L-1" from - http://chemcases.com/cisplat/cisplat04.htm

"The values are for the following conditions: ...the effective concentration of 1 mol/L for each aqueous species" - http://en.wikipedia.org/wiki/Standard_electrode_potential_(data_page)

 

[CalumGemmell]

Actually I think it does matter from what I've read
"The cell potential is a useful value when it can be compared to other cell potentials obtained under the same standard set of conditions—that is, when all participating gases exist at a pressure of 1 atm, and all ions are present in a concentration of 1 mol L-1" from - http://chemcases.com/cisplat/cisplat04.htm

"The values are for the following conditions: ...the effective concentration of 1 mol/L for each aqueous species" - http://en.wikipedia.org/wiki/Standard_electrode_potential_(data_page)

Same conditions, they had the same volume and concentration, so it may still be correct? Also, what was the volume and conc.'s of the electrolytes?

 

[yum135]

Anyone else pick up the mistake?
In the galvanic cell where you had to calculate cell potential the electrolytes weren't 1.0 mol/L therefore the standard potential table had the wrong values and it was impossible to correctly calculate the cell potential.

OMG! I NOTICED IT TOO!! and I was so flustered cause i ddnt know what to do...then just pretended it was 1mol/L LOL!

 

[nichorowitz]

of course i still answered the question but i wrote the examiners a note.
they have given bonus marks in hsc exams before, hopefully if noone else wrote a note to the examiners i might receive one haha

 

[nichorowitz]

Same conditions, they had the same volume and concentration, so it may still be correct? Also, what was the volume and conc.'s of the electrolytes?

nah its definitely not, the values are different

 

[m.jakaran]

It does matter but they would obviously just want you to ignore it. The difference usually isn't that great anyway. Here's a link for the curious:

http://www.ausetute.com.au/nernst.html

 

[zeebobDD]

it does matter, all the chemistry teachers at my school were complaining... though most students didnt even realise the mistake:S

 

[khorne]

Sometimes people like to pretend they are smart. Like this. The table does no specify the conditions. We know it's 1 mol/L but the table simply states "standard potentials". Thus, it is assumed valid for all concentrations for the purpose of the exam.