The chemical reaction that causes chromium to corrode in air is given by:
4Cr + 3O2 → 2Cr2O3
In which 298 K
ΔH°rxn = -2256 kJ
ΔS°rxn = -549.1 J/K
What is the Gibbs free energy for this reaction at 4717 K? Assume that ΔH and ΔS do not change with temperature. Express your answer to two decimal places and include the appropriate units.