14 H2O2 + 12 NH4OH + As2S3 → 20 H2O + 3 (NH4)2SO4 + 2 (NH4)3AsO4

This is an oxidation-reduction (redox) reaction:

2 AsIII - 4 e- → 2 AsV (oxidation)

3 S-II - 24 e- → 3 SVI (oxidation)

28 O-I + 28 e- → 28 O-II (reduction)

As2S3 is a reducing agent, As2S3 is a reducing agent, H2O2 is an oxidizing agent.

Reactants:

  • H2O2 – Hydrogen peroxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Dioxidane source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Oxidanyl source: wikipedia, accessed: 2019-09-27, Perhydroxic acid source: wikipedia, accessed: 2019-09-27
    • Appearance: Very light blue color; colorless in solution source: wikipedia, accessed: 2019-09-27; Colourless liquid source: ICSC, accessed: 2019-09-04; Colorless liquid with a slightly sharp odor. [Note: The pure compound is a crystalline solid below 12°F. Often used in an aqueous solution.] source: NIOSH NPG, accessed: 2019-09-02
  • NH4OH
    • Names: Ammonium hydroxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-07, Ammonia solution source: wikidata, accessed: 2019-09-07, Ammonium hydroxide (10%-35% solution) source: ICSC, accessed: 2019-09-04
    • Appearance: Colourless liquid source: wikipedia, accessed: 2019-09-27; Very volatile colourless ammonia solution in water with pungent odour source: ICSC, accessed: 2019-09-04
  • As2S3 – Arsenic 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

Products:

  • 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
  • (NH4)2SO4 – Ammonium tetraoxosulfate (VI) source: wikipedia, accessed: 2019-09-27
    • Other names: Ammonium sulphate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Ammonium sulfate source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02, Ammonium sulfate (2:1) source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Appearance: Fine white hygroscopic granules or crystals. source: wikipedia, accessed: 2019-09-27
  • (NH4)3AsO4