2 SO3 + 2 CaO → 2 CaSO3 + O2

This is an acid-base reaction (neutralization): SO3 is an acid, CaO is a base.

This is an oxidation-reduction (redox) reaction:

2 SVI + 4 e- → 2 SIV (reduction)

2 O-II - 4 e- → 2 O0 (oxidation)

Reactants:

  • 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
  • CaO – Calcium oxide source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02
    • Other names: Quicklime source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04, Burnt lime source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Unslaked lime source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02source: NIOSH NPG, accessed: 2019-09-02
    • Appearance: White to pale yellow/brown powder source: wikipedia, accessed: 2019-09-27; White hygroscopic crystalline powder source: ICSC, accessed: 2019-09-04; White or gray, odorless lumps or granular powder. source: NIOSH NPG, accessed: 2019-09-02

Products:

  • CaSO3 – Calcium sulfite source: wikipedia, accessed: 2019-09-27source: wikidata, accessed: 2019-09-02
    • Other names: Sulfurous acid source: wikipedia, accessed: 2019-09-27, Calcium salt (1:1) source: wikipedia, accessed: 2019-09-27, E226 source: wikipedia, accessed: 2019-09-27
    • Appearance: White solid 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