Browsing by Author "Subhani, M. S."

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    Radiation Chemistry and Photochemistry of Oxychlorine Ions: Part 1.—Radiolysis of Aqueous Solutions of Hypochlorite and Chlorite Ions
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (5), 1972) Buxton, G. V.; Subhani, M. S.
    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.
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    Radiation Chemistry and Photochemistry of Oxychlorine Ions: Part 2.—Photodecomposition of Aqueous Solutions of Hypochlorite Ions
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (5), 1972) Buxton, G. V.; Subhani, M. S.
    The photodecomposition of alkaline aqueous solutions of hypochlorite ion has been investigated using steady state and flash photolysis techniques. At 365 nm the primary products are O(3P), O–, Cl and Cl– formed by the following processes [graphic omitted] with ϕa= 0.28 ± 0.03 and ϕb= 0.08 ± 0.02. At 313 nm and 253.7 nm O(1D) is also produced ClO–→ Cl + O(1D)(c) and the quantum yields are ϕa= 0.075 ± 0.015, ϕb= 0.127 ± 0.014, ϕc= 0.020 ± 0.015 at 313 nm, and ϕa= 0.074 ± 0.019, ϕb= 0.278 ± 0.016, ϕc= 0.133 ± 0.017 at 253.7 nm. The relative rates of reaction of O(3P) with O2, ClO– and ClO–2 have been found to be in the ratios 1 : 2.8 : 15.9. O(3P) reacts with ClO– and ClO–2 by abstraction of O as well as by addition. A complete reaction mechanism for the photodecomposition of ClO– is proposed.
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    Radiation Chemistry and Photochemistry of Oxychlorine Ions: Part 3.—Photodecomposition of Aqueous Solutions of Chlorite Ions
    (Journal of the Chemical Society : Faraday Transaction - I. The Chemical Society, London. 1972, 68 (5), 1972) Buxton, G. V.; Subhani, M. S.
    The steady state and flash photolysis of aqueous solutions of chlorite ion has been investigated. The primary photodecomposition reactions are ClO–2[graphic omitted]ClO–+ O (a), ClO–2[graphic omitted]ClO–+ O–(b), ClO–2[graphic omitted](ClO–2)*[graphic omitted]ClO2+ ClO–+ O–(c), with the oxygen atom being formed in the 3P state at 365 nm, and in the 1D state at 313 nm and 253.7 nm. (ClO–2)* may be a long lived triplet state of chlorite ion. The primary quantum yields obtained at pH 10 are the following: (i) at 365 nm, ϕa= 0.23 ± 0.03, ϕb=ϕc= 0.077 ± 0.003., (ii) at 313 nm, ϕa= 0.066 ± 0.002, ϕb=ϕc= 0.065 ± 0.003, (iii) at 253.7 nm, ϕa= 0.11 ± 0.005, ϕb=ϕc= 0.08 ± 0.003. A complete mechanism for the photodecomposition is proposed, and the data are consistent with the reaction of O(3P) with ClO–2 proceeding by two paths O(3P)+ ClO–2→ O2+ Cl–+ O(3P)(d), O(3P)+ ClO–2→ ClO–3(e) with kd/ke= 1.50 ± 0.27.