Conditions of the Contact process for sulfuric acid production

Steps:

• Identify the Contact process as the industrial method for converting SO₂ to SO₃ using a catalyst.
• Recall the catalyst is vanadium pentoxide (V₂O₅) for high efficiency.
• Note the temperature range of 400-500°C balances reaction rate and equilibrium yield.
• Confirm pressure is 1-2 atm, as higher pressures are unnecessary for this equilibrium.

Why C is correct:

• Matches the standard conditions: 400-500°C optimizes the exothermic reaction's kinetics and thermodynamics, 1-2 atm suits the gas-phase process, and V₂O₅ catalyzes SO₂ + ½O₂ ⇌ SO₃ effectively.

Why the others are wrong:

• A: Temperature too low (100-200°C slows rate); pressure too high (200 atm unnecessary).
• B: Temperature too low; catalyst Fe is for ammonia synthesis, not sulfuric acid.
• D: Pressure too high (200 atm); catalyst V₂O₃ is incorrect (V₂O₅ required).

Final answer: C