0 votes
29 views
ago in Chemical thermodynamics by (410 points)
Calculate the standard free energy change, ΔG°, for the following redox reaction at 298 K:2Fe3+(aq) + 2I-(aq) → 2Fe2+(aq) + I2(s)The standard reduction potential values for Fe3+ and Fe2+ are -0.037 V and -0.44 V respectively, while the standard reduction potential value for I2 is 0.535 V.

1 Answer

0 votes
ago by (490 points)
To calculate the standard free energy change  G  for the redox reaction, we first need to determine the overall cell potential  E  for the reaction. We can do this by finding the difference in the standard reduction potentials of the two half-reactions.The balanced half-reactions are:Fe3+ aq  + e-  Fe2+ aq   E = -0.037 V  reduction of Fe3+ I2 s  + 2e-  2I- aq      E = 0.535 V  reduction of I2 Since the Fe3+ half-reaction is being reduced and the I2 half-reaction is being oxidized, we need to reverse the I2 half-reaction and change the sign of its standard reduction potential:2I- aq   I2 s  + 2e-     E = -0.535 V  oxidation of I- Now, we can add the two half-reactions and their standard potentials to find the overall cell potential  E :2Fe3+ aq  + 2I- aq   2Fe2+ aq  + I2 s  + 2e- + 2e-E = -0.037 V +  -0.535 V  = -0.572 VNext, we can use the Nernst equation to calculate the standard free energy change  G :G = -nFEwhere n is the number of moles of electrons transferred  in this case, 2 , F is the Faraday constant  96,485 C/mol , and E is the overall cell potential.G = - 2  96,485 C/mol  -0.572 V G = 110,533 J/molSince the standard free energy change is usually expressed in kJ/mol, we can convert the value:G = 110.533 kJ/molSo, the standard free energy change  G  for the redox reaction at 298 K is 110.533 kJ/mol.

Related questions

Welcome to Sarvan Science Q&A, where you can ask questions and receive answers from other members of the community.
...