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)
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.
Of course, I'd be happy to help you with that question!
To calculate the standard free-energy change for a reaction, we can use the equation:
ΔG° = ΣnΔG°f(products) - ΣnΔG°f(reactants)
Where ΔG° is the standard free-energy change, ΣnΔG°f is the sum of the standard free-energy changes of the products and reactants, and n represents the stoichiometric coefficients of the balanced equation.
To begin, we need to look up the standard free-energy values (ΔG°f) for each species involved in the reaction. These values can be found in thermodynamics tables or online databases.
For the reaction you provided:
2Au^+3(aq) + 3Cr(s) → 2Au(s) + 3Cr^+2(aq)
We have the following species: Au^+3(aq), Cr(s), Au(s), and Cr^+2(aq).
Next, we need to find the standard free-energy values (ΔG°f) for each of these species at 25°C. Make sure the values you find are for the same temperature, as they may vary at different temperatures.
Once you have obtained the ΔG°f values for each species, we can substitute them into the equation and calculate the standard free-energy change (ΔG°) for the reaction.
Remember to pay attention to the stoichiometric coefficients of each species and apply them accordingly in the equation.
I hope this explanation helps you understand how to approach the problem. If you have any further questions or need assistance with finding the ΔG°f values or calculations, please let me know!