Which of the following compounds give paramagnetic gas on decomposition
(i) `Pb(NO_(3))_(2)`
(ii) `LiNO_(3)`
(iii) `NaNO_(3)`
(iv) `NH_(4)NO_(2)`

Options

A. I, II, III
B. II, III
C. I, II
D. III, IV

Answer

To determine which of the given compounds produce paramagnetic gases upon decomposition, we will analyze each compound and its decomposition products.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds given are:
- (i) Pb(NO₃)₂ (Lead(II) nitrate)
- (ii) LiNO₃ (Lithium nitrate)
- (iii) NaNO₃ (Sodium nitrate)
- (iv) NH₄NO₂ (Ammonium nitrite)

2. **Decomposition Reactions**:
- **(i) Pb(NO₃)₂**: Upon heating, lead(II) nitrate decomposes to produce nitrogen dioxide (NO₂) and oxygen (O₂):
\[ 2 \text{Pb(NO}_3\text{)}_2 \rightarrow 2 \text{PbO} + 4 \text{NO}_2 + \text{O}_2 \]
Both NO₂ and O₂ are paramagnetic gases because they have unpaired electrons.

- **(ii) LiNO₃**: Lithium nitrate decomposes to produce lithium oxide, nitrogen dioxide, and oxygen:
\[ 2 \text{LiNO}_3 \rightarrow \text{Li}_2\text{O} + 2 \text{NO}_2 + \text{O}_2 \]
Again, both NO₂ and O₂ are paramagnetic.

- **(iii) NaNO₃**: Sodium nitrate also decomposes similarly:
\[ 2 \text{NaNO}_3 \rightarrow 2 \text{Na}_2\text{O} + 2 \text{NO}_2 + \text{O}_2 \]
Here too, NO₂ and O₂ are paramagnetic.

- **(iv) NH₄NO₂**: Ammonium nitrite decomposes to produce nitrogen gas (N₂) and water:
\[ \text{NH}_4\text{NO}_2 \rightarrow \text{N}_2 + 2 \text{H}_2\text{O} \]
Nitrogen gas (N₂) is diamagnetic because it has no unpaired electrons.

3. **Conclusion**: The compounds that produce paramagnetic gases upon decomposition are:
- Pb(NO₃)₂
- LiNO₃
- NaNO₃

Thus, the answer is (i), (ii), and (iii).

### Final Answer:
The compounds that give paramagnetic gas on decomposition are (i) Pb(NO₃)₂, (ii) LiNO₃, and (iii) NaNO₃.