Which gaseous product is formed when a mixture of iron (II) sulphate and potassium nitrated is heated with dilute `H_2SO_4`?

Options

A. `NO`
B. `NO_2`
C. mixture of `NO_2 and N_2O_4`
D. `N_2O_5`

Answer

To solve the question regarding the gaseous product formed when a mixture of iron (II) sulfate and potassium nitrate is heated with dilute sulfuric acid, we can follow these steps:

### Step 1: Identify the Reactants
The reactants in this reaction are:
- Iron (II) sulfate (FeSO₄)
- Potassium nitrate (KNO₃)
- Dilute sulfuric acid (H₂SO₄)

### Step 2: Understand the Reaction Conditions
When these reactants are heated together, a chemical reaction occurs. The dilute sulfuric acid acts as a medium for the reaction.

### Step 3: Determine the Oxidation States
- In iron (II) sulfate (FeSO₄), iron (Fe) has an oxidation state of +2.
- In potassium nitrate (KNO₃), nitrogen (N) has an oxidation state of +5.

### Step 4: Predict the Changes in Oxidation States
During the reaction:
- Iron (Fe) is oxidized from +2 to +3.
- Nitrogen (N) is reduced from +5 to +2.

### Step 5: Write the Balanced Chemical Equation
The balanced equation for the reaction is:
\[ 6 \text{FeSO}_4 + 2 \text{KNO}_3 + 4 \text{H}_2\text{SO}_4 \rightarrow 3 \text{Fe}_2(\text{SO}_4)_3 + \text{K}_2\text{SO}_4 + 2 \text{NO} + 4 \text{H}_2\text{O} \]

### Step 6: Identify the Gaseous Product
From the balanced equation, we can see that the gaseous product formed is nitrogen dioxide (NO).

### Conclusion
The gaseous product formed when a mixture of iron (II) sulfate and potassium nitrate is heated with dilute sulfuric acid is **NO (nitric oxide)**.