Kinetics of the homogenous diazotization of p-nitroaniline with nitrous acid solution using stopped-flow technique

Diazotization is common in the fine chemical industry however its kinetics study is rare. In this work, the stopped-flow technique was adopted to study the kinetic parameters of the diazotization reaction between pnitroaniline and nitrous acid. The results revealed that the p-nitroaniline diazotization is a second-order reaction with excessive hydrochloric acid, and the reaction rate equation with a pre-exponential factor and activation energy of 6.95 x 108 L.mol- 1.s- 1 and 37.79 kJ.mol- 1 respectively was obtained according to Arrhenius equation. In addition, the kinetic model was established, the correlated values of k1 matched well with the experimental values with an AAD of 7.1%. This work provides theoretical data and guidance for its process optimization.