Question

The following standard redox couples are connected to make a galvanic cell. Sn/Sn2+ E1o = -0.14 Zn/Zn2+ E2o = -0.76 Determine the following for the standard galvanic cell: Eo = .62 Correct: Your answer is correct. V Go = 119641.4 Incorrect: Your answer is incorrect. kJ log K = 9.38e20 Incorrect: Your answer is incorrect.

Answer 1

Given  Sn/Sn²⁺ E° = -0.14 V

Zn/Zn²⁺ E° = -0.76 V

Total 2 electrons transferred.

E°cell=-0.14 V - (-0.76 V)=0.62 V

Delta G°=-nFE°cell

where n=2 e^-, F=Faraday constant=96485 C/mol. e^-

Delta G°=-nFE°cell=- (2e^-) x (96485 C/mol. e^-) x (0.62 V)= -119641.4 CV/mol (Since 1CV=1J)

Delta G°=-119641.4 J/mol=-119.64 kJ/mol (Since 1kJ=1000 J)

And we know that Delta G°=-RTlnK

where R=8.314x10^-3 kJ/mol.K and T=298 K

lnK=-Delta G°/RT=-(-119.64 kJ/mol)/(8.314x10^-3 kJ/mol.K x 298 K)

lnK=48.289

K=e^48.289=9.375 x10²⁰

Therefore equilibrium constant, K=9.375 x10²⁰. (logK=log(9.375 x10²⁰)=20.972)

Please me know if you have any doubt. Thank you.