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Redox Equilibria

Given the following redox reactions:

eq_0d8175.gif

How many moles of iron (II) ethandioate FeC2O4 are oxidised by 1 mol of dichromate Cr2O72–(aq)?

(I thought the answer was 2. However the mark scheme says 3, and does not explain why.)
:confused: I dont know, sorry :s-smilie:

I would have said two, as you've got 6e- on the LHS, and 3e- on the right, so I would have doubled the number of moles on the RHS, giving 2 moles...

sorry, that is of no use what so ever...

best to ask teacher tomorrow at college perhaps?

unless someone else can shed some light on this. im curious now, i wonder what we're doing wrong?? :frown:
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Avatar for Gattsu
Gattsu
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Original post by HeatherJarvo
:confused: I dont know, sorry :s-smilie:

I would have said two, as you've got 6e- on the LHS, and 3e- on the right, so I would have doubled the number of moles on the RHS, giving 2 moles...

sorry, that is of no use what so ever...

best to ask teacher tomorrow at college perhaps?

unless someone else can shed some light on this. im curious now, i wonder what we're doing wrong?? :frown:


Thank you. I asked my teacher, he said the mark scheme got it wrong.
Original post by Gattsu
Thank you. I asked my teacher, he said the mark scheme got it wrong.


that's a scary thought isn't it? It's possible to lose marks on the exam by getting the answer correct.... eek!!
Original post by Gattsu
Given the following redox reactions:

eq_0d8175.gif

How many moles of iron (II) ethandioate FeC2O4 are oxidised by 1 mol of dichromate Cr2O72–(aq)?

(I thought the answer was 2. However the mark scheme says 3, and does not explain why.)



Original post by HeatherJarvo
:confused: I dont know, sorry :s-smilie:

I would have said two, as you've got 6e- on the LHS, and 3e- on the right, so I would have doubled the number of moles on the RHS, giving 2 moles...

sorry, that is of no use what so ever...

best to ask teacher tomorrow at college perhaps?

unless someone else can shed some light on this. im curious now, i wonder what we're doing wrong?? :frown:


Couldnt figure out how you form iron (II) ethandioate FeC2O4 in the first place !?
Original post by arvin_infinity
Couldnt figure out how you form iron (II) ethandioate FeC2O4 in the first place !?


Why can you not form it?

(edited 12 years ago)
Original post by thegodofgod
Why can you not form it?



Oh no..I meant , how you form it according the the equation given to you
Original post by arvin_infinity
Oh no..I meant , how you form it according the the equation given to you


Fe2+ + (COOH)2 --> [Fe(COO)2] + 2H+
Original post by charco
Fe2+ + (COOH)2 --> [Fe(COO)2] + 2H+


COOH is not given to us !!!

I guess I misunderstood the question :colondollar:

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