In the presence of perchloric acid, the kinetics and oxidation of phenol, phenoxy acetic acid, and a few para-substituted phenols and phenoxyacetic acids by pyrazinium chlorochromate (PzCC) were investigated in acetic acid and water medium. The reaction was fractional-order for both the substrates and unit order for oxidant and acid. The products of oxidation are quinone. Comparing the reaction rate for phenols and their derivatives revealed a similar behavior. The oxidation and kinetics of phenol and its derivatives are established using the non-linear Hammett plots plot which reveal that para-methyl groups slow down the reaction rate and para-nitro and para-chloro groups speed up the reaction rate. Based on the kinetic data and product analyses, an appropriate mechanism has been provided