Ca(OH)2 + H2SO3 → 2 H2O + CaSO3

This is an acid-base reaction (neutralization): Ca(OH)2 is a base, H2SO3 is an acid.

Reactants:

  • Ca(OH)2 – Calcium hydroxide source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02
    • Other names: {{ubl source: wikipedia, accessed: 2019-09-28, Slaked lime source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02, Calcium hydrate source: wikidata, accessed: 2019-09-02source: ICSC, accessed: 2019-09-04source: NIOSH NPG, accessed: 2019-09-02
    • Appearance: White powder source: wikipedia, accessed: 2019-09-28; Colourless crystals or white powder source: ICSC, accessed: 2019-09-04; White, odorless powder. [Note: Readily absorbs CO2 from the air to form calcium carbonate.] source: NIOSH NPG, accessed: 2019-09-02
  • H2SO3 – Sulfurous acid source: wikipedia, accessed: 2019-09-28source: wikidata, accessed: 2019-09-02
    • Other names: S(O)(OH)2 source: wikidata, accessed: 2019-09-02, Sulphurous acid source: wikidata, accessed: 2019-09-02

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
  • 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