Contact Process (exam Names Only)

Name: Contact Process → H₂SO₄. Catalyst: V₂O₅ (vanadium(V) oxide). Temperature: ~450 °C (school value). Intermediate: oleum (from SO₃ absorbed in conc. H₂SO₄). Product: sulphuric acid H₂SO₄. NOT Haber (Haber = NH₃).

Exams often test recognition of the industrial process for sulphuric acid by name and conditions rather than a full plant diagram. The process is called the Contact Process. The key catalytic oxidation of SO₂ to SO₃ uses V₂O₅ at about 450 °C. SO₃ is absorbed into concentrated sulphuric acid to form oleum; oleum is then diluted carefully with water to give H₂SO₄ of required concentration. That oleum route avoids the violent direct reaction of SO₃ with water alone. Highest-yield mistake to avoid: calling this Haber. Haber is N₂ + 3H₂ ⇌ 2NH₃. Contact is sulphuric acid.

Contact Process makes sulphuric acid. Catalyst name: V₂O₅. Temperature to remember: about 450 °C. Oleum is an intermediate; H₂SO₄ is the product. Haber is different — Haber makes ammonia.

Exam checklist: process name Contact; catalyst V₂O₅; ~450 °C; oleum then H₂SO₄. Be ready to say why oleum is used (safer/controlled absorption of SO₃). State clearly that Haber is ammonia manufacture and must not be mixed with Contact.

The ~450 °C value is a compromise temperature in equilibrium terms for 2SO₂ + O₂ ⇌ 2SO₃ (exothermic forward): lower T favours yield but slows rate; catalyst allows a workable rate at a moderate temperature. Naming V₂O₅ and oleum is usually enough for Class 11 “names only” questions; full flow-sheet detail is optional unless asked.

Contact = H₂SO₄ · V₂O₅ · ~450 °C · oleum · NOT Haber (NH₃).