Interaction between ozone and the chloride ion in sulfuric acid solutions up to 6-M concentration

The effect of sulfuric acid concentration on Cl₂ evolution in the reaction between O₃ and Cl^? has been investigated. The catalytic effects of metal ions in this reaction have been studied as a function of solution acidity. The chlorine evolution rate increases markedly with increasing acid concentration. At acid concentrations below 4 mol/l, the most effective catalyst is Co²⁺. The catalytic activities of Fe³⁺ and Cu²⁺ peak at $C_{H_2 SO_4 } $ = 4.8 mol/l. In passing to highly acidic solutions ( $C_{H_2 SO_4 } $ > 5 mol/l), the catalytic activity of the metal ions decreases, but the chlorine evolution rate remains high owing to the high acidity. Kinetics of VO²⁺ oxidation with ozone in acid media have been studied, and the ozone solubility in aqueous sulfuric acid has been measured.