Condsider the following reaction , Nitrite+Acetic acid +Thiourea `to N_(2) uarr + SCN^(-) + 2H_(2)O` Formation of the product in the above reaction can be identified by:

Options

A. `FeCl_(3)//` dilute `HCl`, when blood red colour appears.
B. `FeCl_(3)//` dilute `HCl`, when blue colour appears.
C. `K_(2)Cr_(2)O_(7)//HCl`, when green colour appear.
D. `KMnO_(4)//HCl`, when colourless solution is formed.

Answer

To identify the products formed in the reaction of nitrite, acetic acid, and thiourea, we can follow these steps:

### Step-by-Step Solution:

1. **Write the Reaction**:
The reaction given is:
\[ \text{Nitrite} + \text{Acetic acid} + \text{Thiourea} \rightarrow \text{N}_2 \uparrow + \text{SCN}^- + 2\text{H}_2\text{O} \]

2. **Identify the Product of Interest**:
The product of interest in this reaction is the thiocyanate ion (\( \text{SCN}^- \)).

3. **Choose a Test for the Product**:
To identify the presence of the thiocyanate ion, we can perform a chemical test using iron(III) ions (\( \text{Fe}^{3+} \)).

4. **Perform the Test**:
When \( \text{SCN}^- \) reacts with \( \text{Fe}^{3+} \) ions (which can be supplied by \( \text{FeCl}_3 \)), a complex is formed:
\[ \text{Fe}^{3+} + \text{SCN}^- \rightarrow \text{[Fe(SCN)]}^{2+} \]

5. **Observe the Color Change**:
The formation of the complex \( \text{[Fe(SCN)]}^{2+} \) results in a blood-red color. This color change indicates the presence of thiocyanate ions in the solution.

6. **Conclusion**:
Therefore, the formation of the blood-red color upon the addition of \( \text{FeCl}_3 \) in dilute HCl confirms the presence of \( \text{SCN}^- \) ions, indicating that the reaction has occurred.

### Final Answer:
The formation of the product in the above reaction can be identified by reacting the solution with \( \text{FeCl}_3 \) in dilute HCl, which will produce a blood-red color.

---