The equilibrium constant for the reaction below is Kc = 9.1 10-6 at 298 K.

Question

2 Fe3+(aq) + Hg22+(aq) 2 Fe2+(aq) + 2 Hg2+(aq)

Calculate G when [Fe3+] = 0.21 M, [Hg22+] = 0.013 M, [Fe2+] = 0.022 M, and [Hg2+] = 0.020 M.

Answer 1

DG = DGo+RTlnK
At equilibrium DG = 0. YOu know Kc; therefore substitute K, R, and T, and solve for DGo.
Then use the first equation above to solve for DG at the concns listed.