The sodium extract of an organic compound on treatment with `FeSO_(4)` solution, `FeCl_(3)` and `HCl` gives red solution. The red colour of

Options

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

Answer

To solve the problem, we need to analyze the reaction that occurs when the sodium extract of an organic compound is treated with FeSO4, FeCl3, and HCl, resulting in a red solution. Here’s the step-by-step solution:

### Step 1: Identify the Sodium Extract
The sodium extract of the organic compound likely contains sodium thiocyanate (NaSCN). This can be formed from the reaction of sodium cyanide (NaCN) with sulfur (S8) when heated.

**Hint:** Consider the possible compounds that can be formed from sodium and sulfur.

### Step 2: Reaction with Iron(III) Chloride
When the sodium thiocyanate (NaSCN) is treated with iron(III) chloride (FeCl3), a complex ion is formed. The thiocyanate ion (SCN-) reacts with Fe3+ ions to form ferric thiocyanate (Fe(SCN)3).

**Hint:** Look for the complex formation between thiocyanate ions and iron ions.

### Step 3: Formation of Ferric Thiocyanate
The reaction can be summarized as follows:
\[ \text{Fe}^{3+} + 3 \text{NaSCN} \rightarrow \text{Fe(SCN)}^{2+} + 3 \text{Na}^+ \]
This ferric thiocyanate complex is responsible for the red color observed in the solution.

**Hint:** Remember that the color change often indicates the formation of a new complex.

### Step 4: Conclusion
The red color in the solution is due to the formation of ferric thiocyanate, which is a well-known red complex. Therefore, the answer to the question is that the red color is due to the formation of ferric thiocyanate (Fe(SCN)3).

**Hint:** Think about the significance of color changes in chemical reactions, particularly in complex ion formation.

### Final Answer
The red color of the solution is due to the formation of ferric thiocyanate (Fe(SCN)3).