5 HCl + 6 FeCl₂ + HClO₃ → 3 H₂O + 6 FeCl₃

This is an oxidation-reduction (redox) reaction:

HClO₃ is an oxidizing agent, FeCl₂ is a reducing agent.

Reactants:

• HCl – Chlorane , Hydrogen chloride
  • Other names: Hydrochloric acid , Hydrochloric acid gas , HCl ... show moreAnhydrous 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.]
• FeCl₂ – Iron(II) chloride , Iron dichloride
  • Other names: Ferrous chloride , Rokühnite , [FeCl3] , FeCl3
  • Appearance: Tan solid (anhydrous) | Pale green solid (di-tetrahydrate) ; White-to-light-green hygroscopic crystals
• HClO₃
  • Names: Chloric acid , Chloric(V) acid , HClO3 ... show more[ClO2(OH)] , Chlorsäure , Chlorate show less
  • Appearance: Colourless solution

Products:

• 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
• FeCl₃ – Iron(III) chloride , Iron trichloride
  • Other names: Ferric chloride , Ferric chloride (anhydrous) , Iron(3+);trichloride ... show moreFerric;trichloride , [FeCl3] , FeCl3 , Iron chloride , Flores martis , Molysite show less
  • Appearance: Green-black by reflected light; purple-red by transmitted light; yellow solid as hexahydrate; brown as solution ; Black-to-brown hygroscopic crystals