The standard free-energy change for the reaction at 25°C is 92640 KJ.
The change in free energy that happens when a compound is created from its constituent parts in their most thermodynamically stable states under standard-state circumstances is known as the standard-state free energy of creation.
There are 6 electrons transferred. The anode half-reaction produces 6 electrons while the cathode half-reaction uses 6 electrons.
For these types of reactions always write out the half-reactions and the appropriate oxidation numbers.
6 electrons are transferred as Au³+ has an oxidation number of 3+ and Au has an oxidation number of 0. 3 electrons are gained for each Au³+ and there are 2 Au³+ in the equation
[tex]2Au^3 (aq) +3cr(s)[/tex] ↽−−⇀ [tex]2Au(s) +3Cr^2[/tex]
Same for Cr to Cr2+ because there are 3 moles of it.
So, n = 6.
F = 96500 J/(V*mol)
where F is faraday's constant.
n = moles of electrons are transferred in this reaction.
Standard emf of the cell, E = cathode - anode.
= 1.49 - 1.33
= 0.16
Using the equation,
ΔG = -nFE
= 6 × 96500 × 0.16
= 92640 KJ
Therefore, the standard free-energy change for the reaction at 25°C is 92640 KJ.
Learn more about standard free energy here:
https://brainly.com/question/10012881
#SPJ4
