2 (HS)^- + 4 HSO₃^- → 3 S₂O₃^2- + 3 H₂O

This is an oxidation-reduction (redox) reaction:

2 S^-II - 8 e^- → 2 S^II (oxidation)

4 S^IV + 8 e^- → 4 S^II (reduction)

HS^- is a reducing agent, HSO₃^- is an oxidizing agent (synproportionation (comproportionation)).

Reactants:

Products:

S₂O₃^2-
H₂O – Water, oxidane
- Other names: Water (H2O) , Hydrogen hydroxide (HH or HOH) , Hydrogen oxide
- Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas

2 (HS)- + 4 HSO3- → 3 S2O32- + 3 H2O