O2 (g) + 2 SO2 (g) → 2 SO3 (l)
This is an oxidation-reduction (redox) reaction:
2 SIV - 4 e- → 2 SVI (oxidation)
2 O0 + 4 e- → 2 O-II (reduction)
SO2 is a reducing agent, O2 is an oxidizing agent.
- 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.]