Brown ppt ,of `Mn(OH)_2` on boiling with `PbO_(2)` and cone `HNO_(3)` yields a pink colouration on dilution due to the formation of

Options

A. `HMnO_(4)`
B. `H_(2)MnO_(4)`
C. `Pb(MnO_(4))_(2)`
D. `PbMnO_(3)`

Answer

To solve the question regarding the brown precipitate of Mn(OH)₂ on boiling with PbO₂ and concentrated HNO₃ yielding a pink coloration on dilution, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants:**
The reactants given are:
- Brown precipitate of Manganese(II) hydroxide, Mn(OH)₂
- Lead(IV) oxide, PbO₂
- Concentrated Nitric acid, HNO₃

2. **Write the Reaction:**
When Mn(OH)₂ reacts with PbO₂ and concentrated HNO₃, the following reaction occurs:
\[ 2 \text{Mn(OH)}_2 + 5 \text{PbO}_2 + 6 \text{HNO}_3 \rightarrow 2 \text{HMnO}_4 + 5 \text{Pb(NO}_3\text{)}_2 + 2 \text{H}_2\text{O} \]

3. **Identify the Product Responsible for the Pink Coloration:**
The product formed in the reaction that gives rise to the pink coloration upon dilution is:
- HMnO₄ (Manganese(VII) hydroxide)

4. **Conclusion:**
Therefore, the pink coloration observed is due to the formation of HMnO₄.

### Final Answer:
The pink coloration on dilution is due to the formation of **HMnO₄**.

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