A solution of `FeCl_(3)` when treated with `K_(4)[Fe(CN)_(4)]` gives a prussian blue precipitate due to the formation of :

Options

A. `Fe[Fe(CN)_(6)]`
B. `K[Fe_(2)(CN)_(6)]`
C. `Fe_(4)[Fe(CN)_(6)]_(3)`
D. `Fe_(3)[Fe(CN)_(6)]_(2)`

Answer

To solve the question regarding the formation of a Prussian blue precipitate when a solution of FeCl₃ is treated with K₄[Fe(CN)₆], we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**:
- We have a solution of FeCl₃ (iron(III) chloride) and K₄[Fe(CN)₆] (potassium ferrocyanide).

2. **Understand the Reaction**:
- When FeCl₃ is mixed with K₄[Fe(CN)₆], a reaction occurs where the iron(III) ions (Fe³⁺) from FeCl₃ interact with the ferrocyanide ions ([Fe(CN)₆]⁴⁻).

3. **Formation of the Complex**:
- The reaction leads to the formation of a complex known as ferric ferrocyanide, which can be represented as Fe₃[Fe(CN)₆]₂. This complex is commonly known as Prussian blue.

4. **Precipitate Formation**:
- The complex Fe₃[Fe(CN)₆]₂ precipitates out of the solution, resulting in a characteristic deep blue color, which is referred to as Prussian blue.

5. **Conclusion**:
- Therefore, the formation of the Prussian blue precipitate is due to the complex Fe₃[Fe(CN)₆]₂.

### Final Answer:
The Prussian blue precipitate is formed due to the complex Fe₃[Fe(CN)₆]₂.

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