J.R. S. answered 07/20/22
Ph.D. University Professor with 10+ years Tutoring Experience
∆Gº = -nFEº = -RT ln K
To find Eº, we first need to find n (number of electrons transferred)
Mg(s) ==> Mg2+ + 2e- ... oxidation
Ni2+ + 2e- ==> Ni(s) ... reduction
Therefore n = 2 mols electrons transferred
∆Gº = -nFEº
-408.0 kJ/mol = -(2 mol e-)(96,500 Coulombs/mol)(Eº)
1 kJ = 1000 coulomb volts, so -408.0 kJ = -408,000 CV
-408,000 CV = -193,000 C (Eº)
Eº = -408,000 C V / -193,000 C
Eº = +2.11 V
To find K, we can use ∆Gº = -RT ln K
∆Gº = -408 kJ/mol
R = 0.008314 kJ/Kmol
T = 298 K
K = ?
-408 = -(0.008314)(298) ln K
-408 = -2.478 ln K
ln K = 164.6
K = 3.1x1071