JEE Main 2021 · 18 March · morning · Single correct · +4 / −1
Match List - I with List - II
Choose the most appropriate answer from the options given below :
| List - I | List - II | ||
|---|---|---|---|
| (a) | Ca(OCl)₂ | (i) | Antacid |
| (b) | CaSO₄.1/2H₂O | (ii) | Cement |
| (c) | CaO | (iii) | Bleach |
| (d) | CaCO₃ | (iv) | Plaster of paris |
- (a) (a) - (i), (b) - (iv), (c) - (iii), (d) - (ii)
- (b) (a) - (iii), (b) - (ii), (c) - (iv), (d) - (i)
- (c) (a) - (iii), (b) - (iv), (c) - (ii), (d) - (i)
- (d) (a) - (iii), (b) - (ii), (c) - (i), (d) - (iv)
Answer and solution
Answer (c) (a) - (iii), (b) - (iv), (c) - (ii), (d) - (i)
Solution
Chemistry ma’am · 2 steps
Match the one you are surest of first: half a water on calcium sulphate is plaster of Paris.
- Use each compound. Think about what each calcium compound does in daily life or in industry. Then pair it with its use.
Compound Common name Why it fits Use Ca(OCl)₂ calcium hypochlorite The OCl⁻ ion is a strong oxidiser and releases chlorine (iii) Bleach CaSO₄.1/2H₂O hemihydrate Mixed with water, it sets back into hard gypsum (iv) Plaster of Paris CaO quicklime It is the main component of cement, about 50 to 60% (ii) Cement CaCO₃ chalk, limestone A mild base that neutralises excess HCl in the stomach (i) Antacid - So. The matching is (a) - (iii), (b) - (iv), (c) - (ii), (d) - (i), which is option (c).
The idea to keep. For calcium compounds, remember the set: hypochlorite bleaches, the hemihydrate is plaster of Paris, quicklime goes into cement, and the carbonate is a gentle antacid.
Answer from the NTA final answer key. Solution by PrepWiser.