where p 1 = 24.6 atm is the pressure of the ideal solution, and p 0 = 1 atm the pressure of the ideal gas phase. We find ∆G fs = 14.9 kJ/mol and ∆G press = 8.0 kJ/mol, and the total single-ion solvation free energy is given by ∆G solv = ∆G sim + ∆G fs + ∆G press .