CaSO3 + 2 HCl → CaCl2 + SO2 + H2O – Balanced equation

Reactants:

• CaSO₃ – Calcium sulfite
  • Other names: Sulfurous acid , Calcium salt (1:1) , E226
  • Appearance: White solid
• HCl – Chlorane , Hydrogen chloride
  • Other names: Hydrochloric acid , M , Uriatic acid
  • Appearance: Colorless, transparent liquid, fumes in air if concentrated ; Colorless gas ; Colourless compressed liquefied gas with pungent odour ; Colorless to slightly yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.]

Products:

• CaCl₂ – Calcium chloride
  • Other names: Calcium(II) chloride , Calcium dichloride , E509
  • Appearance: White powder, hygroscopic ; Odourless hygroscopic colourless or white crystals
• SO₂ – Sulfur dioxide
  • Other names: Sulfurous anhydride , Sulphur dioxide , Sulfurous acid anhydride
  • Appearance: Colorless gas ; Colourless gas or compressed liquefied gas with pungent odour ; Colorless gas with a characteristic, irritating, pungent odor. [Note: A liquid below 14°F. Shipped as a liquefied compressed gas.]
• H₂O – Water, oxidane
  • Other names: Water (H2O) , Hydrogen hydroxide (HH or HOH) , Hydrogen oxide
  • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas