Zucker–Hammett hypothesis

This hypothesis states that, if in an acid catalysed reaction, \(\log _{10}k_{1}\) (first-order @O04322@ of the reaction) is linear in \(H_{0}\) (Hammett @A00081@), water is not involved in the @T06468@ of the @R05139@. However, if \(\log _{10}k_{1}\) is linear in \(\log _{10}\left[\text{H}^{+}\right]\) then water is involved. This has been shown to be incorrect by Hammett himself.
PAC, 1994, 66, 1077. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994)) on page 1176 [Terms] [Paper]