To the aqueous solution of the salt acidified potassium permanganate is added and its colour is discharged. It indicates the absence of

Options

A. `Fe^(+2)`
B. `NO_(3)^(-)`
C. `Be^(+2)`
D. `Sn^(+2)`

Answer

To solve the question, we need to analyze the reaction of acidified potassium permanganate (KMnO4) with the given ions in the salt solution. The color discharge of KMnO4 indicates that it has been reduced, which occurs when it oxidizes another species in the solution.

### Step-by-Step Solution:

1. **Understanding Potassium Permanganate**:
- Potassium permanganate (KMnO4) is a strong oxidizing agent. In acidic medium, it reduces from Mn(VII) to Mn(II), which is colorless.

2. **Analyzing the Given Ions**:
- We have four ions to consider: Fe²⁺, NO₃⁻, Be²⁺, and Sn²⁺.

3. **Reaction with Fe²⁺**:
- Fe²⁺ can be oxidized to Fe³⁺ by KMnO4. The reaction is:
\[ 5 \text{Fe}^{2+} + \text{MnO}_4^{-} + 8 \text{H}^{+} \rightarrow 5 \text{Fe}^{3+} + \text{Mn}^{2+} + 4 \text{H}_2\text{O} \]
- Since Fe²⁺ is oxidized, KMnO4 is reduced, and the color is discharged. Thus, Fe²⁺ does not indicate absence.

4. **Reaction with NO₃⁻**:
- NO₃⁻ (nitrate ion) is in the +5 oxidation state and cannot be oxidized further. Therefore, it does not react with KMnO4, and the color remains purple. This indicates the absence of NO₃⁻.

5. **Reaction with Be²⁺**:
- Beryllium (Be²⁺) is also in its maximum oxidation state (+2) and cannot be oxidized further. Therefore, it will not reduce KMnO4, and the color will remain purple, indicating the absence of Be²⁺.

6. **Reaction with Sn²⁺**:
- Sn²⁺ can be oxidized to Sn⁴⁺ by KMnO4. The reaction is:
\[ 2 \text{MnO}_4^{-} + 5 \text{Sn}^{2+} + 16 \text{H}^{+} \rightarrow 2 \text{Mn}^{2+} + 5 \text{Sn}^{4+} + 8 \text{H}_2\text{O} \]
- Sn²⁺ is oxidized, and the color of KMnO4 is discharged. Thus, Sn²⁺ does not indicate absence.

7. **Conclusion**:
- The ions that do not cause the discharge of the color of KMnO4 are NO₃⁻ and Be²⁺. Therefore, the answer to the question is that the color discharge indicates the absence of NO₃⁻ and Be²⁺.

### Final Answer:
The color discharge indicates the absence of **NO₃⁻** and **Be²⁺**.