OsO₄ + 4 HCl + 2 KCl → K₂(OsCl₄O₂) + Cl₂ + 2 H₂O

This is an oxidation-reduction (redox) reaction:

Reactants:

• OsO₄ – Osmium tetraoxide , Tetraoxoosmium
  • Other names: Osmium tetroxide , Osmium(VIII) oxide , Osmic acid anhydride ... show moreOsmium oxide , Perosmic oxide , Osmic acid , Perosmic acid anhydride , OsO4 show less
  • Appearance: White volatile solid ; Colourless-to-pale-yellow solid in various forms with pungent odour ; Colorless, crystalline solid or pale-yellow mass with an unpleasant, acrid, chlorine-like odor. [Note: A liquid above 105°F.]
• 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.]
• KCl
  • Names: Potassium chloride , Sylvite , Muriate of potash ... show moreKlor-Con M15 , K-Lease , Klor-Con 8 , K+10 , K+8 , Klor-Con M10 , Micro-K 10 , Kato , Kaon Cl-10 , Kaon-Cl , Kaon Cl , Micro-K , Klor-Con 10Meq , Klor-Con 10 , Micro-K Ls , K-dur , Klor-Con , Klor-Con M20 , Slow-K , Ten-K , Klotrix , [KCl] , Kaliumchlorid , Chloride of potash , Kaon-CL 10 , Klor-CON , KCl , Monopotassium chloride , K-Tab , Chlorid draselny , Potassium Chloride show less
  • Appearance: White crystalline solid ; Colourless hygroscopic crystals

Products:

• K₂(OsCl₄O₂)
• 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