K₂Cr₂O₇ (aq) + 14 HCl (aq) → 2 KCl (aq) + 2 CrCl₂ (aq) + 4 Cl₂ (g) + 7 H₂O (l)

This is an oxidation-reduction (redox) reaction:

HCl is a reducing agent, K₂Cr₂O₇ is an oxidizing agent.

This is a gas evolution reaction, Cl₂ is the formed gas.

Reactants:

• K₂Cr₂O₇ – Potassium dichromate(VI)
  • Other names: Potassium dichromate , Chromium potassium oxide , Dipotassium dichromium heptaoxide ... show moreDipotassium dichromate , Dipotassium bichromate , Dichromic acid dipotassium salt , Dipotassium dichromate (VI) , Dichromic acid, dipotassium salt , Potassium bichromate show less
  • Appearance: Red-orange crystalline solid ; Orange-to-red crystals
• 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.]

Products:

• 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
• CrCl₂ – Chromium(II) chloride
  • Other names: Chromous chloride , Chromium dichloride
  • Appearance: White to grey/green powder (anhydrous), very hygroscopic ; Very hygroscopic solid in various forms
• 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