NaI3 + 2 Na2S2O3 → 3 NaI + Na2S4O6

This is an oxidation-reduction (redox) reaction:

NaIII + 2 e- → NaI (reduction)

4 SII - 2 e- → 4 S5/2 (oxidation)

NaI3 is an oxidizing agent, Na2S2O3 is a reducing agent.

Reactants:

  • NaI3
  • 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:

  • NaI
    • Names: Sodium iodide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Sodium iodide (anhydrous) source: ICSC, accessed: 2019-09-04, NaI source: wikidata, accessed: 2019-09-02, Sodium monoiodide source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Appearance: White solid | deliquescent source: wikipedia, accessed: 2019-09-27; Colourless-to-white hygroscopic crystals or white powder. turns brown on exposure to air source: ICSC, accessed: 2019-09-04
  • Na2S4O6
    • Names: Sodium tetrathionate source: wikidata, accessed: 2019-09-03