Which fo the following processes involves smelting

Options

A. `ZnCO_(3) rarrZnO+ CO_(2)`
B. `Fe_(2)O_(3) + 3C rarr 2Fe + 3CO`
C. `2PbS + 3O_(2) rarr 2PbO+ 2SO_(2)`
D. `Al_(2)O_(3). 2H_(2) O rarr Al_(2) O_(3) + 2H_(2)O`

Answer

To determine which of the following processes involves smelting, we first need to understand what smelting is.

### Step-by-Step Solution:

1. **Define Smelting**:
Smelting is a metallurgical process used to extract metals from their ores. It typically involves the use of a reducing agent, often carbon (in the form of coke), to convert metal oxides into pure metals.

2. **Analyze the Given Reactions**:
- **Reaction 1**: ZnCO3 → ZnO + CO2
- This reaction involves the thermal decomposition of zinc carbonate into zinc oxide and carbon dioxide. There is no reduction of metal oxide here, so this is not smelting.

- **Reaction 2**: Fe2O3 + 3C → 2Fe + 3CO
- In this reaction, iron(III) oxide (Fe2O3) reacts with carbon (C) to produce iron (Fe) and carbon monoxide (CO). Here, carbon acts as a reducing agent to extract iron from its oxide, which qualifies as a smelting process.

- **Reaction 3**: PbS + O2 → PbO + SO2
- This reaction involves the oxidation of lead sulfide (PbS) to lead oxide (PbO) and sulfur dioxide (SO2). There is no reduction of metal oxide, so this is not smelting.

- **Reaction 4**: Al2O3 + H2O → Al2O3·nH2O
- This reaction describes the hydration of aluminum oxide, which does not involve any reduction or extraction of metal. Therefore, it is not smelting.

3. **Conclusion**:
Based on the analysis, the only reaction that involves smelting is **Reaction 2: Fe2O3 + 3C → 2Fe + 3CO**.

### Final Answer:
The process that involves smelting is the second reaction: **Fe2O3 + 3C → 2Fe + 3CO**.

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