The chemical formula of Prussian blue is formed by the reaction of ferric ion and ferrocyanide is

Options

A. `K_4[Fe(CN)_6]`
B. `Na_4[Fe(CN)_6]`
C. `Fe_4[Fe(CN)_6]_3`
D. None of these

Answer

To determine the chemical formula of Prussian blue formed by the reaction of ferric ions and ferrocyanide ions, we can follow these steps:

### Step 1: Identify the Ions Involved
- The ferric ion (Fe³⁺) has a charge of +3.
- The ferrocyanide ion (Fe(CN)₆)⁴⁻ has a charge of -4.

### Step 2: Determine the Reaction
- When ferric ions react with ferrocyanide ions, they form a complex. The reaction can be represented as:
\[ 4 \text{Fe}^{3+} + 2 \text{Fe(CN)}_6^{4-} \rightarrow \text{Fe}_3[\text{Fe(CN)}_6]_2 \]
- This indicates that 4 ferric ions combine with 2 ferrocyanide ions.

### Step 3: Write the Chemical Formula
- The resulting compound from the reaction is known as Prussian blue. The chemical formula can be simplified to:
\[ \text{Fe}_3[\text{Fe(CN)}_6]_2 \]
- This can also be expressed as:
\[ \text{Fe}_4[\text{Fe(CN)}_6]_3 \]
- The final formula is often represented as:
\[ \text{K}_4[\text{Fe(CN)}_6] \]

### Step 4: Conclusion
- Therefore, the chemical formula of Prussian blue, which is formed by the reaction of ferric ions and ferrocyanide ions, is:
\[ \text{Fe}_3[\text{Fe(CN)}_6]_2 \text{ or } \text{Fe}_4[\text{Fe(CN)}_6]_3 \]