Abstract
Attempt was made to determine the number of water molecules needed from ground state to transition state in acid-catalyzed hydrolysis of amide. Using relative first-order rate constants and ionization ratios for derivative and standard amide could lead to the medium independence of activity coefficient term in the rate expression of amide acidic hydrolysis. Good linear relationship in the derivation of the relative hydration number (γ'-γ) between derivative (γ') and standard amide (γ) was obtained for the various amide hydrolyses in perchloric acid solutions. The observed (γ'-γ)-values were consistent with the mechanism change and with change in reactivity.
