The effect of ionic strength and buffer choice on the decomposition of tetrathionate in alkaline solutions

The rate of alkaline decomposition of tetrathionate has been measured in nitrogen and air-saturated solutions of varying ionic strength and type of buffer. The rate increases significantly in high ionic strength buffer solutions and is not affected by oxygen. For gold-leaching solutions containing ammonia and ammonium ions, the decomposition of tetrathionate is faster than for carbonate- or phosphate-buffered solutions. These findings explain the discrepancies obtained in the previous studies of this reaction.