SO2 + 2 FeCl3 + 2 H2O → 2 FeCl2 + H2SO4 + 2 HCl
This is an oxidation-reduction (redox) reaction:
SIV - 2 e- → SVI (oxidation)
2 FeIII + 2 e- → 2 FeII (reduction)
SO2 is a reducing agent, FeCl3 is an oxidizing agent.
Reactants:
- SO2 – Sulfur dioxide
- Other names: Sulfurous anhydride , Sulphur dioxide , Sulfurous acid anhydride
- Appearance: Colorless gas ; Colourless gas or compressed liquefied gas with pungent odour ; Colorless gas with a characteristic, irritating, pungent odor. [Note: A liquid below 14°F. Shipped as a liquefied compressed gas.]
- FeCl3 – Iron(III) chloride , Iron trichloride
- H2O – Water, oxidane
Products:
- FeCl2 – Iron(II) chloride , Iron dichloride
- H2SO4 – Sulfuric acid
- HCl – Chlorane , Hydrogen chloride
- Other names: Hydrochloric acid , M , Uriatic acid
- 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.]