How is zinc extracted from its ore? Name the processes involved in the extraction and write chemical equations for the reactions that occur during these processes.
Generated by claude-sonnet-4-6 · 2026-06-15 06:48 · grounding rag
Model Answer
Zinc (as ZnS or ZnCO₃) is extracted by two processes — roasting/calcination (to convert ore to oxide) and reduction (to obtain metal).
Roasting:
$$2\text{ZnS(s)} + 3\text{O}_2\text{(g)} \xrightarrow{\Delta} 2\text{ZnO(s)} + 2\text{SO}_2\text{(g)}$$
Calcination:
$$\text{ZnCO}_3\text{(s)} \xrightarrow{\Delta} \text{ZnO(s)} + \text{CO}_2\text{(g)}$$
Reduction (ZnO reduced by carbon):
$$\text{ZnO(s)} + \text{C(s)} \rightarrow \text{Zn(s)} + \text{CO(g)}$$
Source: Chapter 3, Section 3.4.4
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Explanation
- The question asks for processes named + equations, so name all three (roasting, calcination, reduction) and give all three equations.
- Zinc is a medium-reactivity metal, so carbon-reduction is used (not electrolysis).
- Examiners expect correct state symbols and balanced equations — these are easy marks, don't skip them.
- For 2 marks: naming the processes (½ + ½) + key equations (1 mark) is the likely split. Keep it concise but complete.