Contact Process SO₂ Oxidation
2SO2 + O2 ⇌ 2SO3
Overview
Sulfur dioxide is oxidized to sulfur trioxide over a vanadium pentoxide catalyst in the contact process for sulfuric acid manufacture. Sulfur changes from +4 to +6 oxidation state. The equilibrium is favored by low temperature but requires high temperature for adequate reaction rate, so 400-450 C with V₂O₅ catalyst provides optimal yield.
Participants
| Role | Substance | Coefficient | State |
|---|---|---|---|
| Reactant | Oxygen O | 1 | (g) |
| Reactant | Sulfur Dioxide SO₂ | 2 | (g) |
| Product | Sulfur Trioxide SO₃ | 2 | (g) |
Everyday Example
Sulfuric acid produced by this process is the world's most produced chemical, used in everything from fertilizers to batteries to detergents.
Industrial Importance
The contact process produces over 260 million tonnes of sulfuric acid annually. V₂O₅ catalyst replaced the original, more expensive platinum catalyst.
Properties
- Type
- Redox
- Reversible
- Yes
- Energy
- Exothermic
- ΔH
- -198.0 kJ/mol
- Catalyst
- Vanadium(V) oxide (V₂O₅)
Related Reactions
Aqua Regia Dissolving Gold
Bleaching with Sodium Hypochlorite
Cerium(IV) Reduction by Iron(II)
Chlorine Oxidation of Bromide
Chromate-Dichromate Equilibrium
Copper Displaced by Iron
Copper Oxidation by Nitric Acid
Copper Patina Formation (Verdigris)
Copper Reduction of Silver Ion
Dichromate Oxidation of Ethanol
Frequently Asked Questions
What is the equation for Contact Process SO₂ Oxidation?
The balanced equation is: 2SO₂ + O₂ ⇌ 2SO₃.
What type of reaction is Contact Process SO₂ Oxidation?
Contact Process SO₂ Oxidation is a redox reaction. It is reversible under certain conditions.
Is Contact Process SO₂ Oxidation exothermic or endothermic?
Contact Process SO₂ Oxidation is exothermic (releases energy). The enthalpy change (ΔH) is -198.0 kJ/mol.
What conditions are needed for Contact Process SO₂ Oxidation?
This reaction requires a catalyst (Vanadium(V) oxide (V₂O₅)).