Consider the following two half-reactions and their standard reduction potentials, and answer the three questions below.?
a)Calculate E° for the spontaneous redox reaction that occurs when these two half-reactions are coupled. __________V
b)Calculate the value of ΔG° for the reaction. __________kJ
c)Determine the equilibrium constant for the reaction.
- hcbiochemLv 78 months ago
A spontaneous reaction must have a positive Eo. To get a a spontaneous reaction, you will flip the second half-reaction over, change the sign of its Eo and add them together.
Eo = 1.766 - 1.673 = 0.093 V
b) ΔG° = -n F Eo where n is the number of electron in the balanced equation and F is Faraday's constant. Since one half reaction has 2 electrons and the other 3, the balanced equation will involve the transfer of 6 electrons.
ΔG° = -6 (96485 J/Vmol) (0.093 V) = -5.38X10^4 J/mol or -53.8 kJ/mol
c) ΔG° = - RT ln Keq
-5.38X10^4 J = -8.314 J/molK (298 K) ln Keq
lnKeq = 21.73
Keq = 2.74X10^9