Kinetics of oxidation of N-methyl aniline by chromic acid

The oxidation kinetics of N-methylaniline have been studied by chromic acid in acetic acid water medium. The order of reaction between chromic acid and N-Methylaniline has been studied respectively. The rate constant was found to depend upon the concentration of HCl and H2SO4 acid. With increase in concentration of acid, the rate was found to increase initially up to a certain specific concentration, then the rate constant decreased with further increase in concentration of acid. An addition of natural salts like NaCl, KCl, Na2SO4 and K2SO4 shows negligible effect. The effect of solvent has been studied by varying the composition of acetic acid and has obtained increasing effect of the rate. The effect of catalyst such as Ag+, Cu++ and Mn++ shows increasing effect. Various thermodynamic parameters have been evaluated. The stoichiometry of the reaction has been determined. N,N-dimethyl-benzidine quinone dimine has been identified as the oxidation product of the reaction. A plausible mechanism consistent with experimental result has been suggested.