The sum of the rate constants for solvolysis and scrambling of carbon bridging and nonbridging oxygen‐18 at 4‐MeC6H4CH(CF3)OS(18O2)Tos in 50/50 (v/v) trifluoroethanol/water, (ksolv + kiso) = 5.4 × 10−6 s−1, is 50% larger than ksolv = 3.6 × 10−6 for the simple solvolysis reaction of the sulfonate ester. This shows that the ion‐pair intermediate of solvolysis undergoes significant internal return to form reactant. These data give a value of k‐1 = 1.7 × 1010 s−1 for internal return of the carbocation–anion pair to the substrate. This rate constant is larger than the value of k‐1 = 7 × 109 s−1 reported for internal return of an ion pair between the 1‐(4‐methylphenyl)ethyl carbocation and pentafluorobenzoate anion to the neutral ester (4‐MeC6H4CH(CH3)O2CC6F5) in the same solvent. The partitioning of ion pairs to the 1‐(4‐methylphenyl)ethyl carbocation and to the highly destabilized 1‐(4‐methylphenyl)2,2,2‐trifluoroethyl carbocation is compared and contrasted. Copyright © 2010 John Wiley & Sons, Ltd.