4 HCl + NaNO₃ + 3 FeCl₂ → 2 H₂O + NaCl + NO + 3 FeCl₃

This is an oxidation-reduction (redox) reaction:

NaNO₃ is an oxidizing agent, FeCl₂ is a reducing agent.

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.]
• NaNO₃ – Sodium nitrate
  • Other names: Peru saltpeter , Soda niter , Cubic niter ... show moreNitric acid sodium salt (1:1) , Sodium saltpeter , Nitric acid, sodium salt , Nitrate of soda , Nitric acid monosodium salt , Sodium(I) nitrate (1:1) , Niter , Chile saltpeter show less
  • Appearance: White powder or colorless crystals ; Colourless hygroscopic crystals
• 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

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
• NaCl – Sodium chloride
  • Other names: {{unbulleted list , Salt , Table salt ... show moreCommon salt , NaCl , Broncho saline show less
  • Appearance: Colorless cubic crystals
• NO – Nitrogen monoxide , Oxidonitrogen(•) (additive)
  • Other names: Nitric oxide , Nitrogen(II) oxide , Nitric oxide (radical) ... show moreMononitrogen monoxide , (.)NO , EDRF , Nitrogen monooxide , [NO] , Oxido de nitrogeno(ii) , NO(.) , Oxido nitrico , Stickstoff(ii)-oxid , NO , Oxyde azotique , Oxyde nitrique , Stickstoffmonoxid , Nitrosyl , (NO)(.) , Monoxido de nitrogeno , Endothelium-derived relaxing factor , Nitroxide radical , Nitroxyl , Nitrosyl radical , Hydroxyamine , Nitrogen oxide , Nitrogen protoxide , Nitrosyl hydride , Nitric Oxide show less
  • Appearance: Colourless gas ; Colourless compressed gas ; Colorless gas. [Note: Shipped as a nonliquefied compressed gas.]
• FeCl₃ – Iron(III) chloride , Iron trichloride
  • Other names: {{ubl , Ferric chloride , Ferric chloride (anhydrous) ... show moreIron(3+);trichloride , Ferric;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 {{abbr|aq.|aqueous}} solution ; Black-to-brown hygroscopic crystals