N-factor for the following reaction is
`FeS_(2)toFe_(2)O_(3)+SO_(2)`

Options

A. 8
B. 9
C. 10
D. 11

Explanation

To find the n-factor for the reaction \( \text{FeS}_2 \rightarrow \text{Fe}_2\text{O}_3 + \text{SO}_2 \), we need to determine the change in oxidation states of the elements involved in the reaction. Here’s a step-by-step solution:

### Step 1: Identify the oxidation states of the reactants and products.

- In \( \text{FeS}_2 \):
- Iron (Fe) has an oxidation state of \( +2 \) (since it is bonded to two sulfurs).
- Sulfur (S) has an oxidation state of \( -1 \).

- In \( \text{Fe}_2\text{O}_3 \):
- Iron (Fe) has an oxidation state of \( +3 \).
- Oxygen (O) has an oxidation state of \( -2 \).

- In \( \text{SO}_2 \):
- Sulfur (S) has an oxidation state of \( +4 \).
- Oxygen (O) has an oxidation state of \( -2 \).

### Step 2: Calculate the change in oxidation states for Iron.

- For Iron:
- Change from \( +2 \) (in \( \text{FeS}_2 \)) to \( +3 \) (in \( \text{Fe}_2\text{O}_3 \)).
- The change in oxidation state is \( +3 - (+2) = +1 \).

### Step 3: Calculate the change in oxidation states for Sulfur.

- For Sulfur:
- Change from \( -1 \) (in \( \text{FeS}_2 \)) to \( +4 \) (in \( \text{SO}_2 \)).
- The change in oxidation state is \( +4 - (-1) = +5 \).

### Step 4: Consider the number of atoms involved.

- In the reaction, we have:
- 2 Iron atoms in \( \text{Fe}_2\text{O}_3 \) contributing to the total change.
- 2 Sulfur atoms in \( \text{FeS}_2 \) contributing to the total change.

### Step 5: Calculate the total n-factor.

- For Iron:
- Since there are 2 Iron atoms, the total change for Iron is \( 2 \times 1 = 2 \).

- For Sulfur:
- Since there are 2 Sulfur atoms, the total change for Sulfur is \( 2 \times 5 = 10 \).

### Step 6: Add the contributions to find the overall n-factor.

- Total n-factor = Change from Iron + Change from Sulfur
- Total n-factor = \( 2 + 10 = 12 \).

### Conclusion

The n-factor for the reaction \( \text{FeS}_2 \rightarrow \text{Fe}_2\text{O}_3 + \text{SO}_2 \) is **12**.

---