Given the following reaction at 298 K:
ATP(aq) + H2O(l) → ADP(aq) + Pi(aq) ΔG∘rxn = -30.5 kJ

In a particular cell, the concentrations of ATP, ADP, and Pi are 3.6×10−3 M , 1.2×10−3 M , and 5.1×10−3 M , respectively. Calculate the free energy change for the hydrolysis of ATP under these conditions. (Assume a temperature of 298 K.)