The final step in glycolysis catalyzed by pyruvate kinase couples the hydrolysis of phosphoenolpyruvate (PEP) to the formation of ATP via substrate-level phosphorylation of ADP. If the ΔG°' of ATP + H2O → ADP + Pi + H+ is –30.5 kJ/mol and the ΔG°' of the coupled reaction is –31.4 kJ/mol, what is the ΔG°' of PEP + H2O → pyruvate + Pi?