The Contact Process
This lesson covers:
- The three key stages involved in the contact process for producing sulfuric acid
- The optimal conditions in industry for maximising yield and reaction rate
- The effects of temperature, pressure, and catalysts on the equilibrium position
The contact process for sulfuric acid production The contact process is an industrial method involving reversible reactions for manufacturing sulfuric acid. It comprises three primary steps. |
Step 1: Generation of sulfur dioxide Sulfur is combusted with oxygen to form sulfur dioxide: S₈ + 8O₂ → 8SO₂ |
Step 2: Oxidation of sulfur dioxide Sulfur dioxide is further oxidised using a vanadium (V) oxide catalyst to form sulfur trioxide. 2SO₂ + O₂ ⇄ 2SO₃ |
Step 3: Synthesis of sulfuric acid The sulfur trioxide is reacted with water to form sulfuric acid. SO₃ + H₂O → H₂SO₄ |
Optimisation in industry for yield, rate, and cost
The conditions for producing SO₃ are optimised in industry to balance:
- Yield - The quantity of sulfuric acid produced.
- Rate - The speed at which the reaction occurs.
- Cost - The expenses related to equipment and operation.
Optimal conditions:
- Temperature - High temperatures increase rate of reaction but decrease the yield as the forward reaction is exothermic. A temperature around 450°C offers a balanced compromise.
- Pressure - Higher pressures increase the rate of reaction and the yield but at the expense of increased costs. A pressure around 2 atmospheres is typically used.
- Catalyst - A vanadium (V) oxide catalyst is also used to increase the rate of reaction. It has no effect on the percentage yield.
Which catalyst is used in the contact process to oxidise sulfur dioxide to sulfur trioxide?
Vanadium(V) oxide
Iron(III) oxide
Platinum
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What is the final product of the contact process?
Sulfuric acid
Sulfur dioxide
Sulfur trioxide
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Which factor affects increases the rate but decreases the percentage yield in the contact process?
Pressure
Catalyst
Temperature
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What is the optimal temperature for the contact process to achieve a balanced compromise between yield and reaction rate?
°C
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What is the optimal pressure typically used in the contact process to achieve a higher yield without significantly increasing costs?
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