20. The standard free-energy changes for the reactions below are given.Phosphocreatine - creatine + Pi △G'° = -43.0 kJ/mol
ATP → ADP + Pi △G'° =-30.5 kJ/mol
What is the overall △G'°for the following reaction?
Phosphocreatine + ADP →creatine + ATP (A)-73.5 kJ/mol (B)-12.5 kJ/mol (C) +12.5 kJ/mol (D) +73.5 kJ/mol (E) △G'° cannot be calculated without Keq'.