The rates of alkaline solvolysis of 3- chloropropionate ion at four different temperatures 30, 37, 43 and 57°C in water-tert. butyl alcohol have been measured. The rates of solvolysis were found to be second-order overall and first-order with respect to each 3­chloropropionic acid and hydroxide ions concentrations. There is no simple correlation between the dielectric constant "D" and the rate constant "k". The addition of tert. butyl alcohol to water causes an increase of the rate in a non-linear form. The activation parameters Ea, Ll H, Ll S for the solvolysis reaction pass throug

M A MOUSA ,EL H M DIEFALLAH ,M M ABEDEL BADEI ,M M ASSEM ,