3 H2S (g) + SO3 (l) → 3 H2O (l) + 4 S (s)

This is an oxidation-reduction (redox) reaction:

3 S-II - 6 e- → 3 S0 (oxidation)

SVI + 6 e- → S0 (reduction)

H2S is a reducing agent, SO3 is an oxidizing agent (synproportionation (comproportionation)).

Reactants:

  • H2S – Hydrogen sulfide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02
    • Other names: D source: wikipedia, accessed: 2019-09-27, Ihydrogen monosulfide|Dihydrogen sulfide|Sewer gas|Sulfane|Sulfurated hydrogen|Sulfureted hydrogen|Sulfuretted hydrogen|Sulfur hydride|Hydrosulfuric acid|Hydrothionic acid|Thiohydroxic acid|Sulfhydric acid}} source: wikipedia, accessed: 2019-09-27, Hydrosulfuric acid source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Appearance: Colorless gas source: wikipedia, accessed: 2019-09-27; Colourless compressed liquefied gas with characteristic odour of rotten eggs source: ICSC, accessed: 2019-09-04; Colorless gas with a strong odor of rotten eggs. [Note: Sense of smell becomes rapidly fatigued & can NOT be relied upon to warn of the continuous presence of H2S. Shipped as a liquefied compressed gas.] source: NIOSH NPG, accessed: 2019-09-02
  • SO3 – Sulfur trioxide source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Sulfonylideneoxidane source: wikipedia, accessed: 2019-09-28
    • Other names: Sulfuric anhydride source: wikipedia, accessed: 2019-09-28, Sulfur(VI) oxide source: wikipedia, accessed: 2019-09-28, SO3 source: wikidata, accessed: 2019-09-02
    • Appearance: Colorless to white crystalline solid which will fume in air.{{ source: wikipedia, accessed: 2019-09-28; Fuming hygroscopic colourless liquid or colourless-to-white crystals source: ICSC, accessed: 2019-09-04

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
  • S
    • Names: Sulfur source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04, S source: wikidata, accessed: 2019-09-07, Sulphur source: wikidata, accessed: 2019-09-07source: ICSC, accessed: 2019-09-04
    • Appearance: Yellow solid in various forms source: ICSC, accessed: 2019-09-04