2 NaOH (aq) + SO2 (aq) → H2 (g) + Na2SO4 (aq)
This is an acid-base reaction (neutralization): NaOH is a base, SO2 is an acid.
This is an oxidation-reduction (redox) reaction:
SIV - 2 e- → SVI (oxidation)
2 HI + 2 e- → 2 H0 (reduction)
SO2 is a reducing agent, NaOH is an oxidizing agent.
This is a gas evolution reaction, H2 is the formed gas.
- 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.]