[reaction: see text] The extended Grunwald-Winstein equation has been applied to the specific rates of solvolysis of 2-phenyl-2-ketoethyl bromide and tosylate and the correlation parameters are consistent with an S(N)2 mechanism over the full range of solvents. The k(OTs)/k(Br) ratios are close to unity, consistent with this assignment. Comparisons with the specific rates of solvolysis of 2-phenylethyl bromide and methyl tosylate show only a modest influence upon introduction of the carbonyl group.