My professor never teach us this kind of question before. I don't know why she put this question as a homework since she doesn't teach us this yet. I need help with one question. I don't know where to start. So don't you mind if you can help me please.

Here a question:

Calculate the standard free-energy change for the following reaction at 25 ¡ÆC

2Au^+3(aq) + 3Cr(s) ¡ê 2Au(s) + 3Cr^+2(aq)

2 answers

What you want to do is to calculate Eocell. You get Eocell from
Au^3+ + 3e ==> Au Eo = ? and
Cr ==> Cr^3+ + 3e Eo = ?
Add Eo for the Au (as written) to Eo for Cr (as written).
Then delta Go = -nEocell*F
n will be 6, F is 96,485 and Eocell is from above.
Ok I got it. I got the correct answer. Thank you so much for explain how to start and for your help.