Calculate ΔGº for this reaction at 25 °C

Question

The value of Eºcell for Cr|Cr³⁺||Hg₂²⁺|Hg(l) is 1.78 V. Calculate ΔGº for this reaction at 25 °C

The correct answer is  -1031 kJ

Answer 1

For the balanced redox, 6 electrons will be transferred: 3Hg₂²⁺ + 2Cr ==> 3Hg₂ + 2Cr³⁺

∆Gº = -nFEºcell

n = 6 moles e-

F = 96,485 C/mol e-

Eºcell = 1.78 V = 1.78 J/C

∆Gº = -(6 mol e-)(96.485 C/mol e-)(1.78 J/C)

∆Gº = 1,030,460 J = 1030 kJ