Effect of pH on Oxidation Rate of Aqueous Sodium Sulfite Solution

Abstract

The effect of pH on the oxidation rate of aqueous sodium sulfite solution with cobaltous ion catalyst by oxygen was investigated by a gas absorption method at 25°C.
Measurements were made using solutions of 0.3 and 0.04 mol/l of sodium sulfite with 10^-6 mol/l of cobaltous ion in a region of pH values from 6 to 13.
The relation between the reaction rate and the pH value in solution was too complicated to correlate by a simple expression. Therefore graphical representations for these relationships were shown.
From these figures, it was proved that there was only a limited pH range where one can correlate the reaction rate with pH by simple expressions.
Some useful information was obtained from the observed results in applying the sulfite oxidation method to study the performance of gas-liquid contacting equipment.