Determine standard free energy change for the reaction ATP-> ADP + Pi when ATP = 10M, ADP = 5M and Pi = 5M, at 300 K and ΔG is at equilibrium. (R = 8.314 J/Kmol).

Answer 1

ATP ==> ADP + Pi

At equilibrium K = [ADP][Pi] / [ATP]

K = (5)(5) / (10) = 2.5

Also, at equilibrium, ∆G = 0 and ∆G = ∆Gº + RT ln K

∆G = ∆Gº + RT ln K

0 = ∆Gº + RT ln K

∆Gº = -RT ln K

∆Gº = -(8.314 J/Kmol)(300K) ln 2.5

∆Gº = -2494 x 0.916

∆Gº = -2285 J / mole = 2.29 kJ/ mole