Kinetics of the decolorization of congo red under ultrasonic radiation

Abstract

The fading of the color of the congo red dyestuff at concentrations 0.016. 0.01, and 0.005 g per liter under the influence of ultrasonic radiation from a Mullard generator with barium titanate crystal having a frequency of 1 Mc/sec and power output 225 w has been studied and the reaction is found to be unimolecular, the average velocity constants being respectively, 0.129, 0.209, and 0.193. The fading of congo red is not due to the production of hydrogen peroxide, and it is neither an oxidation nor a reduction process in the ordinary sense. The high cavitation energy appears to be responsible for the breaking down of the molecule of congo red resulting in the color fading.