JEE Main 2021 · 27 August · evening · Single correct · +4 / −1
Match List-I with List-II :
Choose the most appropriate answer from the options given below :
| List - I (Name of ore/mineral) | List - II (Chemical formula) | ||
|---|---|---|---|
| (a) | Calmine | (i) | Zns |
| (b) | Malachite | (ii) | FeCO₃ |
| (c) | Siderite | (iii) | ZnCO₃ |
| (d) | Sphalerite | (iv) | CuCO₃.Cu(OH)₂ |
- (a) (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
- (b) (a)-(iii), (b)-(iv), (c)-(i), (d)-(ii)
- (c) (a)-(iv), (b)-(iii), (c)-(i), (d)-(ii)
- (d) (a)-(iii), (b)-(ii), (c)-(iv), (d)-(i)
Answer and solution
Answer (a) (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i)
Solution
Chemistry ma’am · 3 steps
Read the clue in each name: zinc ores, copper's green ore, and the iron carbonate named after iron.
- Spot the metal. Two formulas contain zinc (ZnCO₃ and ZnS), one contains iron and one contains copper. Calamine and sphalerite are both zinc ores, so the real task is to tell the carbonate from the sulphide.
Ore Metal Formula Match Calamine Zn ZnCO₃, a carbonate (a)-(iii) Malachite Cu CuCO₃.Cu(OH)₂, green basic carbonate (b)-(iv) Siderite Fe FeCO₃, from Greek sideros, iron (c)-(ii) Sphalerite Zn ZnS, zinc blende (d)-(i) - Deciding pair. Options (a) and (b) agree on calamine and malachite. They differ only on siderite and sphalerite. Siderite is the iron ore and sphalerite is the sulphide, which settles it.
- So. The correct match is (a)-(iii), (b)-(iv), (c)-(ii), (d)-(i), which is option (a).
The idea to keep. Learn ores in pairs per metal: zinc gives calamine (ZnCO₃) and zinc blende or sphalerite (ZnS). Iron gives siderite (FeCO₃). Copper gives malachite, the green basic carbonate.
Answer from the NTA final answer key. Solution by PrepWiser.