JEE Main 2021 · 16 March · morning · Single correct · +4 / −1
Match List - I with List - II :
Choose the correct answer from the options given below :
| List - I Industrial process | List - II Application | ||
|---|---|---|---|
| (a) | Haber's process | (i) | HNO₃ synthesis |
| (b) | Ostwald's process | (ii) | Aluminium extraction |
| (c) | Contact process | (iii) | NH₃ synthesis |
| (d) | Hal-Heroult process | (iv) | H₂SO₄ synthesis |
- (a) (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)
- (b) (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii)
- (c) (a)-(ii), (b)-(iii), (c)-(iv), (d)-(i)
- (d) (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)
Answer and solution
Answer (b) (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii)
Solution
Chemistry ma’am · 3 steps
Tie each process to the one product it makes, then pick the option that fits all four.
- Sure ones first. Haber's process makes ammonia, and the Hall-Heroult process is how aluminium is extracted. That already gives (a)-(iii) and (d)-(ii).
Process Key step Product (a) Haber's N₂ + 3H₂ ⇌ 2NH₃ over an Fe catalyst (iii) NH₃ (b) Ostwald's 4NH₃ + 5O₂ → 4NO + 6H₂O over Pt/Rh gauze, then NO → NO₂ → HNO₃ (i) HNO₃ (c) Contact 2SO₂ + O₂ ⇌ 2SO₃ over V₂O₅, then SO₃ is absorbed in H₂SO₄ (iv) H₂SO₄ (d) Hall-Heroult Electrolysis of Al₂O₃ dissolved in molten cryolite (ii) Aluminium - Separate the acids. Ostwald's process starts from ammonia and oxidises it, so nitrogen ends up in HNO₃. The contact process oxidises SO₂ to SO₃ on a catalyst surface, so sulfur ends up in H₂SO₄.
- So. The full match is (a)-(iii), (b)-(i), (c)-(iv), (d)-(ii), which is option (b).
The idea to keep. Learn each industrial process together with its starting material: Haber builds NH₃, Ostwald oxidises that NH₃ to HNO₃, and contact turns SO₂ into H₂SO₄.
Answer from the NTA final answer key. Solution by PrepWiser.