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 (λmax= 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 + O2–(2.4 ± 0.1)× 108, O–+ ClO–2→ ClO2+ O2–(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.