The reaction of sulphite ions in solution with persulphate and pyrosulphate

Abstract If dithionate is obtained by the reaction between persulphate and sulphite, one quarter of the dithionate sulphur comes from the persulphate and three quarters from the sulphite. An explanation is provided for this ratio. If solid pyrosulphate is dissolved in an alkaline solution of sulphite some dithionate is formed. Each of the two reactants contributes half of the dithionate sulphur.