Radiation chemistry and photochemistry of oxychlorine ions. Part 1.—Radiolysis of aqueous solutions of hypochlorite and chlorite ions

Abstract

The radiolysis of aqueous solutions of ClO^– and ClO^–₂ has been investigated using pulse and steady state methods. The absorption spectrum of ClO has been identified (λ_max= 280 nm) and the complete reaction mechanism has been established in the case of ClO^– and proposed in the case of ClO^–₂. The following rate constants have been evaluated (units of M^–1 s^–1): e^–_aq+ ClO^–→ Cl^–+ O^–(5.3 ± 1.0)× 10¹⁰, e^–_aq+ ClO^–₂→ ClO^–+ O^–(4.5 ± 0.5)× 10¹⁰, OH + ClO^–→ ClO + OH^–(9.0 ± 0.5)× 10⁹, OH + ClO^–₂→ ClO₂+ OH^–(6.3 ± 0.5)× 10⁹, O^–+ ClO^–→ ClO + O^2–(2.4 ± 0.1)× 10⁸, O^–+ ClO^–₂→ ClO₂+ O^2–(1.9 ± 0.1)× 10⁸, 2ClO → Cl₂O₂ 1.5 × 10¹⁰(2k)

Values of the radical and molecular yields obtained for dilute alkaline solution are: G(e^–_aq)+G(H)= 2.92 ± 0.05, G(OH)= 2.41 ± 0.12, G(H₂)= 0.42 ± 0.02 and G(H₂O₂)= 0.70 ± 0.01.