Which of the following statements is`//`are correct?

Options

A. In the reaction `MnO_(4)^(2-)+H^(o+)rarrMn^(2+)+?`
the missing product is `MnO_(4)^(ө)`.
B. In the above reaction `(a)`, the missing product is `MnO_(2)`.
C. In the reaction `NO_(2)+H_(2)OrarrNO+` ?
the missing product is `NO_(3)^(ө)`.
D. In the above reaction `(c )`, the missing product is i`NO_(2)^(ө)`.

Explanation

To determine which statements are correct regarding the redox reactions involving manganese (Mn) and nitrogen (N), we need to analyze the oxidation states and the changes occurring in the reactions.

### Step-by-Step Solution:

1. **Identify the given reaction for manganese:**
The reaction provided is:
\[ \text{MnO}_4^{-} + 2 \text{H}^{+} \rightarrow \text{MnO}_2 + \text{missing product} \]

2. **Determine the oxidation state of manganese in the reactants and products:**
- In \(\text{MnO}_4^{-}\), the oxidation state of Mn is +7.
- In \(\text{MnO}_2\), the oxidation state of Mn is +4.
- The missing product is identified as \(\text{MnO}_4^{-}\) (which is incorrect since it should be oxidized).

3. **Analyze the change in oxidation state:**
- The oxidation state of Mn changes from +7 in \(\text{MnO}_4^{-}\) to +4 in \(\text{MnO}_2\). This indicates that Mn is being reduced (gaining electrons).
- Therefore, the missing product should have a higher oxidation state than +7, which is \(\text{MnO}_4^{-}\) (not correct).

4. **Identify the correct missing product:**
- The missing product should be \(\text{MnO}_4^{-}\) which is incorrect as it should be oxidized to a higher state, such as \(\text{MnO}_3\) or \(\text{MnO}_4^{2-}\).

5. **Now analyze the reaction involving nitrogen:**
The reaction provided is:
\[ \text{NO}_2 \rightarrow \text{missing product} \]

6. **Determine the oxidation state of nitrogen in the reactants and products:**
- In \(\text{NO}_2\), the oxidation state of N is +4.
- If the product is to be oxidized, it should have a higher oxidation state. The highest oxidation state of nitrogen is +5, which corresponds to \(\text{NO}_3^{-}\).

7. **Analyze the change in oxidation state:**
- The oxidation state of N changes from +4 in \(\text{NO}_2\) to +5 in \(\text{NO}_3^{-}\). This indicates that N is being oxidized.

8. **Conclusion:**
- The correct missing product for the manganese reaction is not \(\text{MnO}_4^{-}\) but rather a higher oxidation state product.
- The correct missing product for the nitrogen reaction is \(\text{NO}_3^{-}\).

### Final Answer:
- The correct statements are:
- The first statement regarding manganese is incorrect.
- The second statement regarding nitrogen is correct.