6 HCl (aq) + K2Cr2O7 (aq) + 4 Na2SO3 (aq) → 3 H2O (l) + 2 KCl (aq) + 4 Na2SO4 (aq) + 2 CrCl2 (aq)
This is an acid-base reaction (neutralization): HCl is an acid, Na2SO3 is a base.
This is an oxidation-reduction (redox) reaction:
4 SIV - 8 e- → 4 SVI (oxidation)
2 CrVI + 8 e- → 2 CrII (reduction)
Na2SO3 is a reducing agent, K2Cr2O7 is an oxidizing agent.
- HCl – Chlorane , Hydrogen chloride
- Other names: Hydrochloric acid , Hydrochloric acid gas , HCl
- 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.]
- K2Cr2O7 – Potassium dichromate(VI)
- Na2SO3 – Sodium sulfite
- H2O – Water, oxidane
- CrCl2 – Chromium(II) chloride