4 Na2S2O3 3 Na2SO4 + Na2S5

This is an oxidation-reduction (redox) reaction:

5 SII + 12 e- 5 S-2/5 (reduction)

3 SII - 12 e- 3 SVI (oxidation)

Na2S2O3 is both an oxidizing and a reducing agent (disproportionation (dismutation)).

Reactants:

  • Na2S2O3
    • Names: Sodium thiosulfate source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Sodium hyposulfite source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02, Hyposulphite of soda source: wikipedia, accessed: 2019-09-28
    • Appearance: White crystals source: wikipedia, accessed: 2019-09-28; Colourless crystals source: ICSC, accessed: 2019-09-04

Products:

  • Na2SO4
    • Names: Sodium sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Sodium sulphate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Sulfate of sodium source: wikipedia, accessed: 2019-09-27
    • Appearance: White crystalline solid | hygroscopic source: wikipedia, accessed: 2019-09-27; White hygroscopic solid in various forms source: ICSC, accessed: 2019-09-04
  • Na2S5