Hypochlorous acid decomposition in the pH 5-8 region

Luke C. Adam, István Fábián, Kazunori Suzuki, I. Fábián

Research output: Contribution to journalArticle

108 Citations (Scopus)

Abstract

The decomposition of hypochlorous acid in the neutral pH region was studied in 1.0 M NaClO4 from 15 to 50°C. The pKa of HOCl was also determined under these conditions. Hypochlorous acid has a maximum decomposition rate at pH 6.89. The decomposition is a third-order process. The values of ΔH and ΔS are 64.0 ± 0.6 kJ/mol and -67 ± 2 J/mol K, respectively. A mechanism for the decomposition of HOCl is proposed involving Cl2O·H2O and ClO2- as intermediates. Rate constants for the rate-determining steps of the mechanism are presented. Above pH 6, the rate-determining step is proposed to be as follows: OCl- + Cl2O·H2O → HCl2O2- + HOCl. Below pH 6, this process is proposed to be in competition with a parallel pathway: HOCl + Cl2O·H2O → H2Cl2O2 + HOCl. The proposed mechanism was tested by mathematical simulation of the experimental data using the GEAR algorithm. The simulation gives additional support for the proposed mechanism.

Original languageEnglish
Pages (from-to)3534-3541
Number of pages8
JournalInorganic Chemistry
Volume31
Issue number17
Publication statusPublished - 1992

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Hypochlorous Acid
Decomposition
decomposition
acids
Rate constants
simulation

ASJC Scopus subject areas

  • Inorganic Chemistry

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Adam, L. C., Fábián, I., Suzuki, K., & Fábián, I. (1992). Hypochlorous acid decomposition in the pH 5-8 region. Inorganic Chemistry, 31(17), 3534-3541.

Hypochlorous acid decomposition in the pH 5-8 region. / Adam, Luke C.; Fábián, István; Suzuki, Kazunori; Fábián, I.

In: Inorganic Chemistry, Vol. 31, No. 17, 1992, p. 3534-3541.

Research output: Contribution to journalArticle

Adam, LC, Fábián, I, Suzuki, K & Fábián, I 1992, 'Hypochlorous acid decomposition in the pH 5-8 region', Inorganic Chemistry, vol. 31, no. 17, pp. 3534-3541.
Adam LC, Fábián I, Suzuki K, Fábián I. Hypochlorous acid decomposition in the pH 5-8 region. Inorganic Chemistry. 1992;31(17):3534-3541.
Adam, Luke C. ; Fábián, István ; Suzuki, Kazunori ; Fábián, I. / Hypochlorous acid decomposition in the pH 5-8 region. In: Inorganic Chemistry. 1992 ; Vol. 31, No. 17. pp. 3534-3541.
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