To calculate the standard free energy change G for the redox reaction, we first need to determine the standard cell potential Ecell for the reaction. The standard cell potential can be found using the following equation:Ecell = Ecathode - EanodeIn this reaction, Fe2+ is being oxidized to Fe3+, so it is the anode, and Sn4+ is being reduced to Sn2+, so it is the cathode. Therefore, we can plug in the given values:Ecell = ESn4+/Sn2+ - EFe3+/Fe2+Ecell = 0.150 V - 0.771 VEcell = -0.621 VNow that we have the standard cell potential, we can calculate the standard free energy change using the following equation:G = -nFEcellwhere n is the number of moles of electrons transferred in the reaction, F is the Faraday constant 96,485 C/mol , and Ecell is the standard cell potential.In this reaction, 1 mole of electrons is transferred Fe2+ loses 1 electron to become Fe3+, and Sn4+ gains 1 electron to become Sn2+ , so n = 1.Now, we can plug in the values:G = - 1 mol 96,485 C/mol -0.621 V G = 59,923.485 J/molSince the standard free energy change is typically expressed in kJ/mol, we can convert the value:G = 59.923 kJ/molSo, the standard free energy change for the redox reaction is 59.923 kJ/mol.