With `K_(4)[Fe(CN)_(6)],Cu^(2+)` ion gives

Options

A. A blue ppt
B. A bluish green ppt
C. A blood red ppt
D. A reddish brown ppt

Explanation

To solve the question regarding the reaction of \( K_4[Fe(CN)_6] \) with \( Cu^{2+} \) ion, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants:**
- The reactants in this case are \( K_4[Fe(CN)_6] \) (Potassium ferrocyanide) and \( Cu^{2+} \) (Copper(II) ion).

2. **Understand the Reaction:**
- When \( K_4[Fe(CN)_6] \) reacts with \( Cu^{2+} \), a complex compound is formed. The \( Cu^{2+} \) ion will combine with the ferrocyanide ions from \( K_4[Fe(CN)_6] \).

3. **Write the Reaction Equation:**
- The reaction can be represented as:
\[ K_4[Fe(CN)_6] + CuSO_4 \rightarrow Cu_2[Fe(CN)_6] + 2 K_2SO_4 \]
- Here, \( Cu_2[Fe(CN)_6] \) is the complex formed, and \( K_2SO_4 \) is produced as a byproduct.

4. **Identify the Precipitate:**
- The complex \( Cu_2[Fe(CN)_6] \) is known to form a reddish-brown precipitate when \( Cu^{2+} \) ions react with ferrocyanide ions.

5. **Conclusion:**
- The final products of the reaction are \( Cu_2[Fe(CN)_6] \) (reddish-brown precipitate) and \( 2 K_2SO_4 \) (potassium sulfate).

### Final Reaction:
\[ K_4[Fe(CN)_6] + CuSO_4 \rightarrow Cu_2[Fe(CN)_6] \downarrow + 2 K_2SO_4 \]