Long-lasting large amplitude periodic change of the pH is measured in an aqueous suspension of CaSO3-H2O2-HCO 3- at 2.0-10.0 °C in a closed reactor. The amplitude can be as large as 2 pH units between pH 5 and 7. The observed phenomenon is explained and simulated by taking into account a slow dissolution of CaSO 3, which serves as a continuous supply of HSO3- for a H+-producing autocatalytic composite reaction between H 2O2 and HSO3-. Protonation of HCO3- to form CO2 in a reversible reaction provides for the necessary negative feedback in [H+].
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry