The rate constants for three competing processes at the chiral center in the acid-catalyzed racemization of (R)-1-phenyl-1-propanol and (R)-1-phenyl-1-butanol at 64.5 +/- 1.0 OC have been determined by chiral HPLC and GC/MS methods : oxygen exchange without inversion, k(E), oxygen exchange with inversion, k(EI), and inversion without exchange, k(I). These same rate constants, previously determined for natural abundance 1-phenylethanol in 50% O-18-enriched water, have been reevaluated for this compound by following the kinetics of 91% O-18-enriched alcohol in natural abundance water. These latter data strengthen the evidence that, for 1-phenylethanol, the departing water, in some cases, bonds to the opposite face of the intermediate carbocation as indicated by a non-zero value for k(I); this process is also operative in the reactions of the other two alkanols as shown by similar kinetic data. In terms of substitution reactions with the solvent leading to oxygen exchange, phenylpropanol behaves similarly to phenylethanol in that k(E) < k(EI); whereas, for phenylbutanol, k(E) approximate to K-EI. A common mechanism in which the initially formed carbocation is present as a complex with the departing water, an ion-molecule pair, can account for the variations in the relative rate constants for the oxygen exchange reactions of these three alcohols. The rate of motion of water molecules within the solvation sphere of these intermediates relative to their exchange with the bulk solvent to form randomly solvated carbocations differs, depending on the substituent at the chiral center. The variations in the rate constants for the oxygen exchange reactions reflect these differences in water mobility.