Contact Process Conditions for SO₂ to SO₃

Steps:

• Identify catalyst: Vanadium(V) oxide accelerates the reaction without being consumed.
• Recall temperature: 400–450°C optimizes rate and yield for exothermic equilibrium.
• Recall pressure: 100–200 kPa (1–2 atm) shifts equilibrium right per Le Chatelier's principle.
• Match options: Select row with correct catalyst and pressure near 200 kPa.

Why D is correct:

• Vanadium(V) oxide is the standard catalyst; 200 represents ~200 kPa pressure, aligning with typical 1–2 atm to favor product formation.

Why the others are wrong:

• A: Iron is incorrect catalyst (V₂O₅ used); 2000 kPa is excessively high.
• B: Vanadium(V) oxide correct, but 200 likely °C (too low for reaction rate).
• C: Vanadium(V) oxide correct, but 2000 likely °C (impossibly high, would decompose reactants).

Final answer: D