20 HCl + 4 K2CrO4 + 3 P2O3 → H2O + 8 KCl + 6 H3PO4 + 4 CrCl3
This is an acid-base reaction (neutralization): HCl is an acid, K2CrO4 is a base.
This is an oxidation-reduction (redox) reaction:
6 PIII - 12 e- → 6 PV (oxidation)
4 CrVI + 12 e- → 4 CrIII (reduction)
P2O3 is a reducing agent, K2CrO4 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.]
- K2CrO4 – Potassium chromate
- H2O – Water, oxidane
- CrCl3 – Chromium(III) chloride , Chromium trichloride