Sonochemical behavior of aqueous solutions of iodide, bromide and azide

The sonolysis of azide solutions was investigated. The main product is nitrogen, which is formed in the reaction of N3− with OH radicals in the millimolar concentration range. At higher azide concentration, additional nitrogen is formed as hydrogen atoms are scavenged. Ammonia and hydrazine are minor products of the N3− sonolysis. Solutions of iodide and bromide are also irradiated under pH conditions where reactions of the products, i.e., hydrogen per oxide and iodide (or bromide) do not occur. The total yield of the products as well as the hydrogen yield is independent of the solute concentration. The results are understood in terms of the competition of the OH+OH and the OH+solute reactions. A local concentration of 4 × 10−3 mol/L of the OH radicals in an interfacial region between the cavitation bubbles and the liquid is derived from the data obtained.