Regarding brown ring complex formation, Which of the following statement is wrong ?

Options

A. NO formation takes place
B. `Fe_(2)(SO_(4))_(3)` is used in this process
C. `Fe^(+2)` and `NO_(3)^(-)` both are reduced
D. Formula of brown ring complex is `[Fe(H_(2)O)_(5)NO^(-)]^(+2)`

Explanation

To solve the question regarding the brown ring complex formation and identify which statement is wrong, we will analyze the process step-by-step.

### Step 1: Understand the Brown Ring Test
The brown ring test is a qualitative analysis test used to detect the presence of nitrate ions (NO3-) in a solution. It involves the reaction of ferrous sulfate (FeSO4) with concentrated sulfuric acid (H2SO4) and a nitrate salt.

**Hint:** Recall the components involved in the brown ring test: FeSO4, H2SO4, and a nitrate salt.

### Step 2: Reaction Overview
When ferrous sulfate (FeSO4) is mixed with a nitrate salt in the presence of concentrated sulfuric acid, a series of reactions occur. The ferrous ion (Fe2+) gets oxidized, and the nitrate ion (NO3-) gets reduced to nitric oxide (NO).

**Hint:** Identify the oxidation and reduction processes occurring in the reaction.

### Step 3: Write the Chemical Reaction
The balanced chemical reaction can be summarized as follows:
\[ 3 \text{FeSO}_4 + 2 \text{H}_2\text{SO}_4 + 6 \text{HNO}_3 \rightarrow \text{Fe}_2(\text{SO}_4)_3 + 3 \text{NO} + 4 \text{H}_2\text{O} \]

From this reaction, we can see that:
- Fe2+ is oxidized to Fe3+.
- NO3- is reduced to NO.

**Hint:** Pay attention to the products formed and the changes in oxidation states.

### Step 4: Identify the Brown Ring Complex
The brown ring complex formed in the test consists of the iron ion (Fe2+) coordinated with nitric oxide (NO) and water molecules. The formula for the brown ring complex is typically represented as [Fe(H2O)5NO]2+.

**Hint:** Remember the composition of the brown ring complex and its charge.

### Step 5: Analyze the Statements
Now, we need to evaluate the provided statements:
- **Option A:** NO formation takes place.
- **Option B:** Fe2+ is oxidized, not reduced.
- **Option C:** The formula of the brown ring complex is correct.
- **Option D:** NO has no charge.

Based on the analysis:
- **Option A** is correct because NO is indeed formed.
- **Option B** is correct because Fe2+ is oxidized to Fe3+.
- **Option C** is correct as the formula for the brown ring complex is accurately represented.
- **Option D** is incorrect because NO is neutral (it does not carry a charge).

### Conclusion
The wrong statement among the options is **Option D**.

**Final Answer:** The wrong statement is **Option D** (NO has no charge).