Water soluble salt (x) when heated decomposes into three products A, B and C. Here B and C are two different paramagnetic gases while A is yellow in hot condition Here the salt (x) is

Options

A. `Hg(NO_3)_2`
B. `FeC_2O_4`
C. `ZnSO_4`
D. `Pb(NO_3)_2`

Answer

To solve the problem, we need to identify the water-soluble salt (x) that decomposes upon heating into three products: one yellow compound (A) and two different paramagnetic gases (B and C).

### Step-by-Step Solution:

1. **Understanding the Products**:
- We know that A is yellow when hot, and B and C are paramagnetic gases.
- Paramagnetic substances have unpaired electrons, which makes them attracted to magnetic fields.

2. **Analyzing Possible Salts**:
- We need to consider common water-soluble salts that decompose upon heating and produce gases.

3. **Testing Each Salt**:
- **Option 1: Hg(NO3)2**
- Decomposes to Hg (green), NO2 (paramagnetic), and O2 (paramagnetic).
- A (Hg) is green, not yellow. So, this option is incorrect.

- **Option 2: FeC2O4**
- Decomposes to FeO (black), CO2 (diamagnetic), and CO (paramagnetic).
- CO2 is not paramagnetic, so this option is incorrect.

- **Option 3: ZnSO4**
- Decomposes to ZnO (white), SO2 (paramagnetic), and O2 (paramagnetic).
- ZnO is white, not yellow. So, this option is incorrect.

- **Option 4: Pb(NO3)2**
- Decomposes to PbO (yellow), NO2 (paramagnetic), and O2 (paramagnetic).
- PbO is yellow, and both NO2 and O2 are paramagnetic. This fits all criteria.

4. **Conclusion**:
- The water-soluble salt (x) that meets all the conditions is **Pb(NO3)2**.

### Final Answer:
The water-soluble salt (x) is **Pb(NO3)2**.