2 As2S3 (s) + 9 O2 (g) 2 As2O3 (s) + 6 SO2 (aq)

This is an oxidation-reduction (redox) reaction:

6 S-II - 36 e- 6 SIV (oxidation)

18 O0 + 36 e- 18 O-II (reduction)

As2S3 is a reducing agent, O2 is an oxidizing agent.

Reactants:

  • As2S3Arsenic trisulfide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Arsenic(III) sulfide source: wikipedia, accessed: 2019-09-27
    • Appearance: Orange crystals source: wikipedia, accessed: 2019-09-27
  • 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

Products:

  • As2O3Diarsenic trioxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04
    • Other names: Arsenic trioxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Arsenic(III) oxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Arsenic sesquioxide source: wikipedia, accessed: 2019-09-27
    • Appearance: White solid source: wikipedia, accessed: 2019-09-27; White lumps or crystalline powder source: ICSC, accessed: 2019-09-04
  • SO2Sulfur dioxide source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Sulfurous anhydride source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Sulphur dioxide source: ICSC, accessed: 2019-09-04source: wikidata, accessed: 2019-09-02, Sulfurous acid anhydride source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Appearance: Colorless gas source: wikipedia, accessed: 2019-09-28; Colourless gas or compressed liquefied gas with pungent odour source: ICSC, accessed: 2019-09-04; Colorless gas with a characteristic, irritating, pungent odor. [Note: A liquid below 14°F. Shipped as a liquefied compressed gas.] source: NIOSH NPG, accessed: 2019-09-02