NaHSO₃ (aq) + Cl₂ (g) + H₂O (l) → NaHSO₄ (aq) + 2 HCl (aq)

This is an oxidation-reduction (redox) reaction:

NaHSO₃ is a reducing agent, Cl₂ is an oxidizing agent.

Reactants:

• NaHSO₃ – Sodium hydrogen sulfite
  • Other names: Sodium bisulfite , E222 , Sodium bisulphite ... show moreSodium bisulfite 38-40 % aqueous solution , Monosodium salt of sulfurous acid , Sodium acid bisulfite , Bisulfite de sodium , Sodium hydrogensulfite , Natriumbisulfit , Saures Natriumsulfit , Primäres Natriumsulfit , Natriumhydrogensulfit , Sodium acid sulfite , Sodium sulhydrate , Sodium hydrogensulfite aqueous solution , Sodium metabisulfite aqueous solution , Monosodium sulfite , Leucogen , Hydrogen sulfite sodium , Sulfurous acid, monosodium salt show less
  • Appearance: White solid ; Colourless-to-yellow liquid with characteristic odour ; White crystals or powder with a slight odor of sulfur dioxide.
• Cl₂
  • Names: Chlorine , Molecular chlorine
  • Appearance: Greenish-yellow compressed liquefied gas with pungent odour ; Greenish-yellow gas with a pungent, irritating odor. [Note: Shipped as a liquefied compressed gas.]
• H₂O – Water, oxidane
  • Other names: Water (H2O) , Hydrogen hydroxide (HH or HOH) , Hydrogen oxide ... show moreDihydrogen monoxide (DHMO) (systematic name) , Hydrogen monoxide , Dihydrogen oxide , Hydric acid , Hydrohydroxic acid , Hydroxic acid , Hydrol , Μ-oxido dihydrogen , Κ1-hydroxyl hydrogen(0) show less
  • Appearance: White crystalline solid, almost colorless liquid with a hint of blue, colorless gas

Products:

• NaHSO₄ – Sodium hydrogen sulfate
  • Other names: Sodium bisulfate , Sodium acid sulfate , Bisulfate of soda
  • Appearance: White solid
• HCl – Chlorane , Hydrogen chloride
  • Other names: Hydrochloric acid , M , Uriatic acid ... show moreHydronium chloride , Chlorhydric Acid , Hydrochloric acid gas , HCl , Anhydrous hydrogen chloride , Hydrochloric acid, anhydrous , Aqueous hydrogen chloride , [Note: Often used in an aqueous solution.] show less
  • 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.]