Which of the following compound gives paramagnetic gas on heating :-

Options

A. `LiNO_(3)`
B. `NaNO_(3)`
C. `KNO_(3)`
D. All of these

Answer

To determine which of the given compounds produces a paramagnetic gas upon heating, we will analyze each option step by step.

### Step 1: Analyze LiNO3 (Lithium Nitrate)
- **Heating Reaction**: When lithium nitrate (LiNO3) is heated, it decomposes to form lithium oxide (Li2O), nitrogen dioxide (NO2), and oxygen (O2).
- **Gas Produced**: The gas produced in this reaction is O2.
- **Paramagnetism**: O2 (oxygen) is known to be a paramagnetic gas because it has unpaired electrons.

### Step 2: Analyze NaNO3 (Sodium Nitrate)
- **Heating Reaction**: Sodium nitrate (NaNO3) upon heating decomposes to form sodium nitrite (NaNO2) and oxygen (O2).
- **Gas Produced**: The gas produced is again O2.
- **Paramagnetism**: As established earlier, O2 is paramagnetic.

### Step 3: Analyze KNO3 (Potassium Nitrate)
- **Heating Reaction**: When potassium nitrate (KNO3) is heated, it decomposes to form potassium nitrite (KNO2) and oxygen (O2).
- **Gas Produced**: The gas produced is O2.
- **Paramagnetism**: O2 is still paramagnetic.

### Conclusion
Since all three compounds (LiNO3, NaNO3, and KNO3) produce oxygen (O2) gas upon heating, and since O2 is a paramagnetic gas, we can conclude that all of these compounds give a paramagnetic gas upon heating.

### Final Answer
The correct answer is **Option D**: All of the above compounds (LiNO3, NaNO3, KNO3) give a paramagnetic gas (O2) on heating.

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