Thermal Decomposition of Sulfuric Acid
H2SO4 → H2O + SO3
Overview
Concentrated sulfuric acid decomposes at high temperatures (above 340 C) into water vapor and sulfur trioxide gas. This is the reverse of the hydration reaction that produces sulfuric acid. The equilibrium shifts toward decomposition at high temperatures.
Participants
| Role | Substance | Coefficient | State |
|---|---|---|---|
| Reactant | Sulfuric Acid H₂SO₄ | 1 | (l) |
| Product | Water H₂O | 1 | (g) |
| Product | Sulfur Trioxide SO₃ | 1 | (g) |
Everyday Example
This decomposition is relevant to understanding why concentrated sulfuric acid fumes in hot weather and must be stored properly.
Industrial Importance
This equilibrium is important in sulfuric acid concentration processes and in the lead-chamber and contact processes for sulfuric acid manufacturing.
Properties
- Type
- Decomposition
- Reversible
- Yes
- Energy
- Endothermic
- ΔH
- 177.0 kJ/mol
Related Reactions
Cracking of Octane (Thermal Cracking)
Decomposition of Ammonium Nitrate
Decomposition of Barium Peroxide
Decomposition of Calcium Carbonate (Calcination)
Decomposition of Calcium Hypochlorite
Decomposition of Carbonic Acid
Decomposition of Hydrogen Peroxide
Decomposition of Iron(II,III) Oxide (Direct Reduction)
Decomposition of Nitroglycerin
Decomposition of Nitrous Oxide (Laughing Gas)
Frequently Asked Questions
What is the equation for Thermal Decomposition of Sulfuric Acid?
The balanced equation is: H₂SO₄ → H₂O + SO₃.
What type of reaction is Thermal Decomposition of Sulfuric Acid?
Thermal Decomposition of Sulfuric Acid is a decomposition reaction. It is reversible under certain conditions.
Is Thermal Decomposition of Sulfuric Acid exothermic or endothermic?
Thermal Decomposition of Sulfuric Acid is endothermic (absorbs energy). The enthalpy change (ΔH) is 177.0 kJ/mol.