Chemistry question

Question

Calculate ΔG° for the following reaction:

Mn (s) + Zn2+ (aq)→Mn2+(aq)+Zn(s)

−4.10×104 J

+3.74×105 J

−8.10×104 J

Answer 1

Oxidation reaction:

Mn(s) ==> Mn2+ + 2e- Eºoxid = 1.19 V

Reduction reaction:

Zn2+ + 2e- ==> Zn(s) Eºred = -0.76

Eºcell = 1.19 - 0.76 = 0.43 V

∆Gº = -nFEºcell

n = # electrons = 2

F = Faraday const. = 96,485 C/mol e-

E = 0.43 V

∆Gº = -(2)(96,485)(0.43)

∆Gº = -41,487 J/mol = -41.5 kJ/mol