2 SO2 (g) + O2 (g) 2 SO3 (l)

This is an oxidation-reduction (redox) reaction:

2 SIV - 4 e- 2 SVI (oxidation)

2 O0 + 4 e- 2 O-II (reduction)

SO2 is a reducing agent, O2 is an oxidizing agent.

Reactants:

  • 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
  • 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:

  • SO3Sulfur 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