4 Na2S + 3 O2 + 4 H2O → 4 NaOHH + 2 Na2S2O3

This is an oxidation-reduction (redox) reaction:

4 S-II - 16 e- → 4 SII (oxidation)

2 O0 + 4 e- → 2 O-II (reduction)

4 O0 + 12 e- → 4 O-III (reduction)

Na2S is a reducing agent, O2 is an oxidizing agent, O2 is an oxidizing agent.

Reactants:

  • Na2S
    • Names: Sodium sulfide source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02, Disodium sulfide source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02, Sodium sulfide (anhydrous) source: ICSC, accessed: 2019-09-04
    • Appearance: Colorless, hygroscopic solid source: wikipedia, accessed: 2019-09-28; White-to-yellow hygroscopic crystals with characteristic odour source: ICSC, accessed: 2019-09-04
  • O2
    • Names: Dioxygen source: wikidata, accessed: 2019-09-07, Oxygen source: ICSC, accessed: 2019-09-04source: wikidata, accessed: 2019-09-07, Oxygen (liquefied) source: ICSC, accessed: 2019-09-04
    • Appearance: Odourless compressed gas source: ICSC, accessed: 2019-09-04; Liquefied gas. colourless-to-blue extremely cold liquid source: ICSC, accessed: 2019-09-04
  • H2O – Water, oxidane source: wikipedia, accessed: 2019-09-27
    • Other names: Water (H2O) source: wikipedia, accessed: 2019-09-27, Hydrogen hydroxide (HH or HOH) source: wikipedia, accessed: 2019-09-27, Hydrogen oxide source: wikipedia, accessed: 2019-09-27
    • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas source: wikipedia, accessed: 2019-09-27

Products:

  • NaOHH
  • 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