The dissolution rate and solubility of amorphous silica were determined in pure water, a sodium chloride solution and a sodium sulfite solution in the concentration range of 10 -3-10 -1 M. The initial dissolution rate (0-12 hours) was enhanced in the presence of Na +, while it was not. affected by Cl - and SO 3 2-. Although the solubility in pure water was the same as that in a NaCl solution, the solubility in a Na 2SO 3 solution increased depending on its concentration, suggesting the formation of complexes of silicic acid with sulfite ion. The conditional formation constants of the hypothetical 1:1 complex were estimated to be 105-1951 M -1 based on difference between the solubility of amorphous silica in the sodium sulfite solution and that in sodium chloride solution.
All Science Journal Classification (ASJC) codes
- Analytical Chemistry