Undergraduate Laboratory Experiments in Sonochemistry using an Ultrasonic Bath

Abstract

Two undergraduate experiments in sonochemistry are presented. The first experiment involves the sonication of aqueous solutions of potassium iodide. Sonication of aqueous media generates hydroxyl radicals, which oxidizes iodide to triodide. Triiodide is measured spectrophotometrically. Sonication is performed with an ultrasonic cleaning bath. Solutions are sonicated in 13 x 100 mm test tubes that, coincidentally, make suitable cuvettes for the Spectronic-20 teaching-laboratory spectrophotometers used in the experiment. An optional version of the experiment is to compare rates of triiodide production under air vs. nitrogen. The second experiment involves the oxidation and bleaching of water-soluble dyes in aqueous solutions. The chemical kinetics exhibited in each experiment are discussed.