2 As + 3 H2SO4 → 2 H3AsO3 + 3 SO2
This is an oxidation-reduction (redox) reaction:
2 As0 - 6 e- → 2 AsIII (oxidation)
3 SVI + 6 e- → 3 SIV (reduction)
As is a reducing agent, H2SO4 is an oxidizing agent.
Reactants:
Products:
- H3AsO3 – Arsorous acid
- 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.]