Polythionic acid

Polythionic among the oxygen acids of sulfur with the general empirical formula H2S2 No6 and HO3S -Sn -SO 3 H (n = 1, 2, 3, ... 11). Polythionic acids are relatively stable in aqueous solutions. The resistance decreases with increasing sulfur content. The resistance of their salts increases in acid solution by tri- to hexathionate to and Octathionat again. In alkaline solution, the resistance of the polythionates decreases with increasing sulfur content.

Representation

By introducing hydrogen sulfide into a solution of sulfur dioxide ( sulphurous acid ) to give a colorless and odorless solution " Wackenrodersche liquid " which includes primarily tetrathionic H2S4O6 and pentathionic H2S5O6.

Meaning and usage

The tetrathionate ion is formed in the Iodometry.