Identifiy the correctly matched pair.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Calamine $ZnCO_3$.
Let us evaluate each option to determine the correct match between the ore and its chemical formula.
1. Bauxite [Al₂(OH)₄Si₂O₅]:
Incorrect. Bauxite is the primary ore of aluminum, but its formula is typically Al₂O₃ · xH₂O, not the given formula. The formula given here is incorrect and seems to describe a silicate compound, not bauxite.
2. Malachite Cu₂S:
Incorrect. Malachite is a copper ore, but its correct formula is Cu₂CO₃(OH)₂ (basic copper carbonate). The formula Cu₂S refers to chalcocite, another copper ore.
3. Calamine ZnCO₃:
Correct. Calamine is an ore of zinc, and its correct formula is ZnCO₃ (zinc carbonate). This is the correctly matched pair.
4. Cuprite CuFeS₂:
Incorrect. Cuprite is an oxide ore of copper, and its correct formula is Cu₂O. The formula CuFeS₂ corresponds to chalcopyrite, another copper ore.
Conclusion:
The correct pair is Calamine ZnCO₃.