<span style="font-size:13.0pt;mso-bidi-font-size: 10.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:AR-SA" lang="EN-GB">Sodium chlorite-iodine-methyl acetoacetate oscillatory reaction investigated by UV-vis spectrophotometry</span>

Abstract

A new sodium chlorite-iodine-methyl acetoacetate chemical oscillatory reaction has been studied UV-vis spectrophotometrically. The initial concentrations of methyl acetoacetate, sodium chlorite, iodine and sulfuric acid, and, the <i style="mso-bidi-font-style:normal">p</i>H of the system influence the oscillation observed at wavelength of 297 nm. There is a pre-oscillatory or induction period and the amplitude and the number of oscillations depend on the initial concentration of the reactants. The induction time decreases linearly with the initial concentration of methyl acetoacetate. The oscillatory reaction can be accelerated by increasing the temperature. The induction and the oscillation periods have two different apparent activation energies, i.e., <span style="mso-bidi-font-weight:bold">52.83 kJ/mol and 29.12 kJ/mol, respectively, <span style="mso-bidi-font-weight: bold">indicating that the two stages have different reaction mechanisms. Generating the enol isomer by keto-enol tautomerism is an important step to constrain the time of induction period.

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