Computer simulations of the free energy associated with different conformations of a single n-dodecane molecule in liquid water are reported. The alkane chain was monitored as a function of the end-to-end distance, essentially following the formation of a hairpin bend from an initially fully extended state. While elongated conformations are among the most stable state in both gas and solvated states, the influence of the solvent is to favor more compact states. At the most compact conformation, the hairpin bend, the solvent imparts a stabilizing free-energy contribution of 6 kJ/mol. The torsional strain of bending the molecule into this hairpin conformation is partly relieved by the reduction of entropically unfavorable water molecules associated with the reduction in the alkane’s surface exposed area. The resultant solvent contribution to the free-energy change is characterized by an unfavorable enthalpic and a competing favorable entropic (-T Delta S) contribution. The conformational change associated with the transition from an extended state to a compact state for n-dodecane is accompanied by a relatively small, non-uniform change in surface exposed area. A simplified model of the free energy as a function of this area can account for the gross effects but is unable pick up the molecular details inherent in the system.