Table 1.

Normalized hydration energetics (kcal/mol at 25 °C)

Solute	−TΔSo/n	ΔHo/n	ΔGo/n
Data set I
Methane	0.227	−0.128	0.098
Ethane	0.259	−0.179	0.079
Propane	0.256	−0.184	0.072
Isobutane	0.249	−0.173	0.077
Neopentane	0.249	−0.170	0.078
Data set II
Ethane	0.261	−0.182	0.080
Propane	0.249	−0.177	0.072
Butane	0.259	−0.189	0.070

Hydration free energy (ΔG^o), enthalpy (ΔH^o), and entropy (ΔS^o) for the hydration of gaseous alkanes; T is degrees K. The standard state is the one proposed by Ben-Naim (16) for solute transfer between fixed positions in the gas and liquid phases. n is the number of water molecules correlated with the alkane by vdw attraction, taken from ref. 13. ASA is the solvent-accessible surface area in Ų, using the vdw radii given in ref. 19.