JEE Main 2021 · 17 March · evening · Single correct · +4 / −1
Match List - I with List - II :
Choose the correct answer from the options given below :
| List - I | List - II | ||
|---|---|---|---|
| (a) | Haematite | (i) | Al₂O₃ . xH₂O |
| (b) | Bauxite | (ii) | Fe₂O₃ |
| (c) | Magnetite | (iii) | CuCO₃ . Cu(OH)₂ |
| (d) | Malachite | (iv) | Fe₃O₄ |
- (a) (a)-(i), (b)-(iii), (c)-(ii), (d)-(iv)
- (b) (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
- (c) (a)-(ii), (b)-(iii), (c)-(i), (d)-(iv)
- (d) (a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)
Answer and solution
Answer (b) (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)
Solution
Chemistry ma’am · 3 steps
Two iron oxides here: haematite is the red Fe₂O₃, magnetite is the magnetic Fe₃O₄.
- Sort by metal. Haematite and magnetite are iron ores, bauxite is the aluminium ore, and malachite is a copper ore. That splits List II at once: the two iron oxides, one aluminium oxide and one copper carbonate.
- Tell the irons apart. Haematite (from the Greek for blood) is red Fe₂O₃, with iron only in the +3 state. Magnetite is the black, magnetic mixed oxide Fe₃O₄, which is FeO.Fe₂O₃.
Ore Metal Formula Match (a) Haematite Fe Fe₂O₃ (ii) (b) Bauxite Al Al₂O₃.xH₂O (i) (c) Magnetite Fe Fe₃O₄ (iv) (d) Malachite Cu CuCO₃.Cu(OH)₂ (iii) - So. The matching is (a)-(ii), (b)-(i), (c)-(iv), (d)-(iii), which is option (b).
The idea to keep. Learn ores in pairs of name and formula, grouped by metal. For iron: haematite Fe₂O₃, magnetite Fe₃O₄, siderite FeCO₃, iron pyrites FeS₂.
Answer from the NTA final answer key. Solution by PrepWiser.