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 determine the gaseous product formed when a mixture of iron (II) sulfate (FeSO₄) and potassium nitrate (KNO₃) is heated with dilute sulfuric acid (H₂SO₄), 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 Type
This reaction is a redox reaction. In redox reactions, there is a transfer of electrons where one species gets oxidized and another gets reduced.

### Step 3: Determine Oxidation States
- In FeSO₄, iron (Fe) is in the +2 oxidation state (Fe²⁺).
- In KNO₃, nitrogen (N) is in the +5 oxidation state (N⁵⁺).

### Step 4: Write the Balanced Chemical Equation
When the mixture is heated, the following reaction occurs:
\[ 6 \text{FeSO}_4 + 2 \text{KNO}_3 + 4 \text{H}_2\text{SO}_4 \rightarrow 3 \text{Fe}_2(\text{SO}_4)_3 + \text{K}_2\text{SO}_4 + 2 \text{NO} + 4 \text{H}_2\text{O} \]

### Step 5: Identify the Products
From the balanced equation, we can see that:
- Iron (Fe) is oxidized from +2 to +3, forming ferric sulfate (Fe₂(SO₄)₃).
- Nitrogen (N) is reduced from +5 to +2, forming nitric oxide (NO) gas.

### Step 6: Conclusion
The gaseous product formed in this reaction is **nitric oxide (NO)**.

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

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