`FeCr_(2)O_(4)(` chromite `)` is converted to `Cr` by following steps `:`
Chromite `overset(I)rarrNa_(2)CrO_(4)overset(II)rarrCr_(2)O_(3)overset(III)rarr Cr`
Reagents in `I,II,` and `III` step might be `:`

Options

A. `Na_(2)CO_(3)//"air",triangle" "C "C`
B. `Na_(2)CO_(3)//"air",triangle" "C, triangle" "Al, triangle`
C. `NaOH//"air",triangle" "C,triangle" "Al,triangle`
D. `NaOH//triangle" "Al//triangle" "C,triangle`

Explanation

To convert chromite (FeCr₂O₄) to chromium (Cr) through the specified steps, we can break down the process as follows:

### Step-by-Step Solution:

1. **Step I: Conversion of Chromite to Sodium Chromate**
- **Reaction**: FeCr₂O₄ + NaOH + O₂ (from air) → Na₂CrO₄ + Fe₂O₃ + H₂O
- **Reagent**: Sodium Hydroxide (NaOH) and Oxygen (O₂) from air.
- **Explanation**: Chromite is treated with sodium hydroxide in the presence of air. This leads to the formation of sodium chromate (Na₂CrO₄) and iron(III) oxide (Fe₂O₃).

2. **Step II: Conversion of Sodium Chromate to Chromium Trioxide**
- **Reaction**: 2 Na₂CrO₄ + C → Cr₂O₃ + 2 Na₂CO₃
- **Reagent**: Carbon (C).
- **Explanation**: The sodium chromate is then heated with carbon, which reduces the chromate to chromium(III) oxide (Cr₂O₃) while producing sodium carbonate (Na₂CO₃).

3. **Step III: Reduction of Chromium Trioxide to Chromium**
- **Reaction**: Cr₂O₃ + 2 Al → 2 Cr + Al₂O₃
- **Reagent**: Aluminium (Al).
- **Explanation**: Finally, chromium(III) oxide is reduced to metallic chromium using aluminium as a reducing agent.

### Summary of Reagents:
- **Step I**: Sodium Hydroxide (NaOH) and Oxygen (O₂)
- **Step II**: Carbon (C)
- **Step III**: Aluminium (Al)

### Final Answer:
The reagents in steps I, II, and III are Sodium Hydroxide (NaOH), Carbon (C), and Aluminium (Al) respectively.

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