In the reaction `MnO_(4)^(-)+SO_(3)^(-2)+H^(+)rarrSO_(4)^(-2)+Mn^(2+)+H_(2)O`

Options

A. `MnO_(4)^(-) and H^(+)` both are reduced
B. `MnO_(4)^(-)` is reduced and `H^(+)` is oxidised
C. `MnO_(4)^(-)` is reduced and `SO_(3)^(2-)` is oxidised
D. `MnO_(4)^(-)` is oxidised and `SO_(3)^(2-)` is reduced

Answer

To analyze the given redox reaction:

**Reaction:**
\[ \text{MnO}_4^- + \text{SO}_3^{2-} + \text{H}^+ \rightarrow \text{SO}_4^{2-} + \text{Mn}^{2+} + \text{H}_2\text{O} \]

We need to determine which species are oxidized and reduced by calculating the oxidation states of the elements involved.

### Step 1: Determine the oxidation state of manganese in \(\text{MnO}_4^-\)

1. In \(\text{MnO}_4^-\), let the oxidation state of Mn be \(x\).
2. The oxidation state of oxygen is \(-2\), and there are 4 oxygen atoms.
3. The equation is:
\[ x + 4(-2) = -1 \]
\[ x - 8 = -1 \]
\[ x = +7 \]
So, the oxidation state of Mn in \(\text{MnO}_4^-\) is \(+7\).

### Step 2: Determine the oxidation state of manganese in \(\text{Mn}^{2+}\)

1. The oxidation state of Mn in \(\text{Mn}^{2+}\) is \(+2\).

### Step 3: Determine the change in oxidation state for manganese

1. The change in oxidation state for Mn is:
\[ +7 \rightarrow +2 \]
This indicates a decrease in oxidation state, meaning Mn is reduced.

### Step 4: Determine the oxidation state of sulfur in \(\text{SO}_3^{2-}\)

1. In \(\text{SO}_3^{2-}\), let the oxidation state of S be \(y\).
2. The equation is:
\[ y + 3(-2) = -2 \]
\[ y - 6 = -2 \]
\[ y = +4 \]
So, the oxidation state of S in \(\text{SO}_3^{2-}\) is \(+4\).

### Step 5: Determine the oxidation state of sulfur in \(\text{SO}_4^{2-}\)

1. In \(\text{SO}_4^{2-}\), let the oxidation state of S be \(z\).
2. The equation is:
\[ z + 4(-2) = -2 \]
\[ z - 8 = -2 \]
\[ z = +6 \]
So, the oxidation state of S in \(\text{SO}_4^{2-}\) is \(+6\).

### Step 6: Determine the change in oxidation state for sulfur

1. The change in oxidation state for S is:
\[ +4 \rightarrow +6 \]
This indicates an increase in oxidation state, meaning S is oxidized.

### Step 7: Analyze the hydrogen ions

1. In the reaction, \(\text{H}^+\) is converted to \(\text{H}_2\text{O}\).
2. The oxidation state of hydrogen in \(\text{H}^+\) is \(+1\) and in \(\text{H}_2\text{O}\) it is also \(+1\).
3. There is no change in oxidation state for hydrogen, so it is neither oxidized nor reduced.

### Conclusion

- **MnO4^-** is reduced (oxidation state decreases from +7 to +2).
- **SO3^{2-}** is oxidized (oxidation state increases from +4 to +6).
- **H^+** remains unchanged.

Thus, the correct answer is: **MnO4^- is reduced and SO3^{2-} is oxidized.**