HCl (aq) + SO₃ (l) → HSO₃Cl (l)

Reactants:

• 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.]
• SO₃ – Sulfur trioxide , Sulfonylideneoxidane
  • Other names: Sulfuric anhydride , Sulfur(VI) oxide , SO3 ... show moreSulphur trioxide , [SO3] , Sulphuric (acid) anhydride , Sulfuric oxide show less
  • Appearance: Colorless to white crystalline solid which will fume in air.{{ ; Fuming hygroscopic colourless liquid or colourless-to-white crystals

Products:

• HSO₃Cl – Sulfurochloridic acid
  • Other names: Chlorosulfuric acid , Chlorosulfonic acid , Chlorosulphonic acid ... show moreChlorinesulfonic acid , Chlorinesulphonic acid , Chloridosulfonic acid , Chloridosulphonic acid , Sulfuric chlorohydrin show less
  • Appearance: Colorless liquid that fumes in air ; Colourless-to-yellow liquid with pungent odour